
Class T_^%.^L^ 

Book T-t. 

Copyright}]^ 



COPYRIGHT DEPOSIT. 



FOUNDRY PRACTICE 



A TREATISE ON MOLDING AND CASTING 
IN THEIR VARIOUS DETAILS 



By 

JAMES M. TATE 



AND 



MELVIN O. STONE, M. E. 



Prepared for the use of students in the College of Engineering 
University of Minnesota 



MINNEAPOLIS 
THE H. W. WILSON COMPANY 

1904 



LI6S7aiTV «* nONGRHSS 
Two OoRtes Rftreived 

SEP 6 1904 

_ Cooyrlsrht Entrv 
CLASS ft- XXc. No 

Of i^ ^ I 1^ 

' COPY B 



Copyright, 1904 

BY 

James M. Tate 



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INTRODUCTION 

In administering the work in foundry practice at the 
University of Minnesota, the want of a good text book 
has been a serious disadvantage. The work of the shop 
and that of the class room should be correlated — shop 
work should be studied and discussed in the class room, 
and examples illustrating the various principles under- 
lying good practice should be worked out in the shop. 

While there have been some excellent books written 
upon the subject of foundry practice, yet, as a rule, these 
have been written with the needs of the experienced 
molder in view rather than those of the beginner. For 
this reason it is a difficult matter to teach the subject so 
that the student will acquire an intelligent understand- 
ing of its various details. The nomenclature and shop 
phraseology are not sufficiently elementary for the aver- 
age beginner to grasp the statement presented, and much 
time is frequently spent in explaining an author's mean- 
ing. 

The present little treatise has been written with a full 
knowledge of the problems involved and with the object 
of lessening some of the difficulties which arise in teach- 
ing tJ"' subject. The authors are both men of wide ex- 
perience in foundry practice and its correlated subjects. 
Air. Tate is an experienced pattern maker, who has been 
in charge of the pattern shop at the University of Min- 
nesota for the past fifteen years, and during a part of 
this time he has also had charge of the work in the foun- 
dry. Mr. Stone is a graduate of the University, who has 
given especial attention to foundry work, both from the 



iv INTRODUCTION 

standpoint of the chemist and from that of the molder. 

In piesenting this work on foinidry practice, the 
authors reahze that it is not a complete treatise on the 
subject. The aim has been to produce a book in which 
the principles of foundry practice are set forth concisely 
and clearly ; with the needs of the engineering student 
in view rather than those of the practical foundryman. 
To this end numerous examples are given representa- 
tive of the different kinds of molding, and it is believed 
that the simple methods used in illustrating and describ- 
ing the various operations involved and the reasons there- 
for will give the student a ready knowledge of the details 
of molding which will go far to supplement the practical 
work of the foundry, which, in a college course, must 
necessarily be limited. 

While the treatment is thus somewhat brief, the sub- 
ject matter as here presented is intended to cover all 
ordinary work in foundry practice including both brass 
and iron casting. 

A glossary of foundry terms has been added, as it 
has been found that to obtain the greatest value from a 
work "of this character, the reader must become familiar 
with names and expressions used by foundrymen, for 
even if it were possible to eliminate shop expressions, 

it would be undesirable to do so. 

J. J. Flather. 
Professor of Mechanical E7igi?teerino, 

Mififieapo/is, Miniiesota. University of Minnesota. 

Septejnber, igo^. 



The authors wish to acknowledge their indebtedness to Mr. 
E. A. Johnson, Instructor in Foundry Practice at the University 
of Minnesota, and also to other foundrymen for information and 
suggestions received in the preparation of their work. 



FOUNDRY PRACTICE 

CHAPTER I 

A sand suitable for molding must be open to allow 
the escape of gases and must be able to hold a given 
form to withstand pressure and wash of the metal. 
Such a sand has a percentage of clay or binding ma- 
terial which will hold the mass together firmly when 
dampened and compressed. If the percentage of clay 
becomes too great, the sand is too close when com- 
pressed, SO' the gases cannot pass off ; then the metal will 
not lie quietly against the face of the sand. 

The molding sands used in diiTerent parts of the 
country vary greatly in their composition. Those high 
ni clay must be used with as little water as possible and 
must not be compressed or rammed much as the mold 
must give free escape for gases through the sand. 
The coarse sands very low in clav may require much 
water and hard ramming in order to form a satisfactorv 
mold. The tempering and ramming of the sand must 
be largely gauged by the nature of the sand the molder 
has at hand. 

Tempering the sand means the mixing and wetting 
of the sand ready for making a mold. It is otherwise 
known as cutting over the sand. 

The sand should be mixed evenly and to a dampness 



2 FOUNDRY PRACTICE 

such that it will stick together when squeezed in the 
hand, but not so wet as to show moisture or dampen 
the hand. The sand pile should be opened out so that 
there will be no holes in which the water will accumu- 
late. The water should then be thrown over the sand 
ni thin sheets by swinging the pail with the bottom 
slightly ahead of the top. In this manner the water is 
distributed evenly and does not cause mud in spots. If 
the sand is wet excessively in spots as by throwing the 
water on the pile in a body, it requires much more shov- 
elling to obtain an even temper, hence loss of time. The 
sand should then be shovelled over in order to mix 
thoroughl}-. The shovelling should be done so^ as to 
scatter the sand when casting it from the shovel. This 
is accomplished by giving the handle of the shovel a 
twist just as the sand is leaving it. When wishing to 
throw the sand to a distant point, it should be allowed 
to leave the shovel in a solid mass, but this does not mix 
it evenly. In mixing, a space should always be kept be- 
tween the pile from which the sand is taken and the 
one to which it is thrown. If this is not observed some 
of the sand will not be thoroughly mixed. After the 
sand has been shovelled over once it seldom is found 
to be mixed thoroughly, which makes it preferable to 
cut it over from two to three times. All the water 
necessary for the proper tempering should be put on 
before shovelling over the sand the last time. When 
trying to find whether the sand needs more water or 
not the hand should be forced into the pile to get some 
sand from the interior from which to determine its 
temper. This should be done at several points. The 
sand from the interior from which to determine its 
that in the heap. When only a little more water is 



FOUNDRY PRACTICE 3 

necessary it should be sprinkled on by throwing the 
water from the pail with the hand. 

The molder or helper should learn to shovel either 
right- or left-handed, so as to be able to take either 
side of the heap when working with an assistant. 

The riddle is the sieve used for sifting the sand. 
Its meshes range from 2 to the inch to 16 or 32 per 
inch. They are numbered according to the number 
of meshes per inch, as a No. 2 riddle means one having 
y2 in. meshes, a No. 4 has Yx in. meshes, a No-. 16 has 
ViG ii'i- meshes, etc. In some places the riddles having 
the mesh finer than ^ in. are called sieves. 

In riddling sand by hand, the riddle should be held 
loosely in the hand and carried by the fingers so that 
the palm of the hand will strike the rim as it is cast 
from side to side. Hitting the rim of the riddle in this 
way jars loose the sand that sticks to the riddle, keeps 
the meshes open better, and allows the sand to pass 
through more freely. By practice in holding the riddle 
in this manner, a rocking swing may be obtained which 
jars the riddle at each turn and carries but very little 
weight on the fingers. It is often found of advan- 
tage, especially in fine riddles, to put some irons in with 
the sand, as gaggers, etc. These irons scrape the wires 
clean and add to the jarring of the riddle. 

When not in use, the riddle should always be hung 
up on a nail or placed on the sand heap with the screen 
up. If left with the screen resting on the sand, the 
meshes become clogged, thus hindering the passage of 
the sand through the screen. 

There are many forms of mechanical sand sifters. 
The two representative forms of pneumatic sifters are 



4 FOUNDRY PRACTICE 

shown in Figs. 93 and 96, while the belt-driven sifters 
are shown in Figs. 98 and 99. 

Facing sand is placed next to the pattern in making 
a mold in order that the sand will peel or part from 
the casting freely and leave a smooth surface. Facing 
sand contains a percentage of sea coal and usually new 
sand, dependent upon the kind of work for which it is 
to be used. 

The percentage of sea coal varies greatly, depending 
upon the thickness of metal and type of casting. The 
limits are i part of sea coal to 2 parts of sand, and i 
part of sea coal to 16 to 20 parts of sand. The limiting 
proportions are very seldom used. The usual propor- 
tions are from i to 6, to i to 14 of sand, depending on 
the thickness of the metal. When the metal is thinner 
than ^2 in. no facing is necessary. Better and smoother 
castings are obtained in this case by using heap sand 
riddled through a fine riddle onto the pattern. For 
metal between y'l in. and i in. the proportion should 
be about i part of sea coal to 12 or 14 parts of sand; 
between i in. and 2 in., i part of sea coal to 8 or 10 parts 
of sand; above 2 in., i part of sea coal to 6 or 8 parts of 
sand. 

The sand used in the facing may also vary in its 
proportion of new and old sand. This is dependent up- 
on the sand used. The most general proportion is 1 
part of new sand to from 3 to^ ■; parts of old sand. 
Greater percentages of new^ sand mav h^ used on 
heavy work. The limiting case is a facing made of 
entirely new sand for the cope of very heavy work. 

It is not always the thickness of the casting that 
regulates the strength of the facing sand. There are 
many other things to be considered: (i) whether the 



FOUNDRY PRACTICE 5 

casting is to be poured with hot or dull iron; (2) the 
distance of some parts of the mold from the gate; (3) 
the time it will take the mold to become filled with iron ; 

(4) whether the metal is running over flat surfaces, and 

(5) is covering them slowly or quickly. Then again, 
heavv solid castings have become "cold-shot'' owing 
to the use of facings that were weak in proportion to 
the casting, caused by the slow rising of the metal in 
pouring. Strong facings on the sides oi a mold, where 
the iron enters and rises slowly, may easily cause heavv 
castings to be ''cold-shot." Again, the square corners 
of castings should, in general, have weaker facings than 
the straight, plain surfaces. The lower parts of deep 
molds should have a stronger facing than the upper por- 
tion, because the metal becomes dull while rising to the 
top of the mold. If the facing suitable for the lower 
portion were used at the upper, the casting at the upper 
part would become curly or partly cold-shot at the sur- 
face. A new sand without mixture will require more 
sea coal than if it were mixed with old or common 
heap sand. 

A thorough mixing of the facing is necessary. If 
the sea coal is not evenly mixed, it often causes the 
casting to be streaked, veined, or cold-shot. 

In mixing by hand it is almost impossible to dis- 
tribute the sea coal evenly, therefore it is important that 
it should be handled several times in order to come as 
near as possible to a thorough mixture. 

In mixing, the old and new sand should be kept as 
dry as possible when shovelled over in order to mix 
well. The sea coal is added while the sand is spread 
out thin. The whole is cut over once or twice, then rid- 
dled through a No. 6 or 8 riddle. It is then tramped 



FOUNDRY PRACTICE 



down and water put on to^ give the proper temper, as in 
the case of tempering the heap s-md. It is again cut 
over to mix the wet and dry sand, then riddled through 
a No. 4 riddle. It is now ready to be riddled onto the 
pattern. The mixture should always be riddled twice, 
and better still, three or four times It is best to use 
sand quite dry to start the mixture, as when wet the 
sea coal sticks in small balls and does not mix well. 
In large foundries, the facing sand is mixed by a 




Fig. I. 

facing machine which gives a mixture of exact propor- 
tions and more thoroughly mixed than can be done by 
hand. 

The frame in which a mold is made is called a flask. 
It is composed of two or more parts. The bottom part 
is trailed the drag or nowel, the top part is called the 
cope, and the intermediate parts, when used, are called 
the cheek. Plasks are made of wood or iron. 

The form of flask used for small patterns when 



' FOUNDRY PRACTICE 7 

the pressure of the metal is very little, is represented in 
Fig. I. These are called snap flasks. They are hinged 
at one corner and fasten at the diagonal corner with a 
snap. The mold is rammed in the flask and when ready 
for pouring the flask is unsnapped and removed. 
Thus many molds may be made with a single 
flask. Before casting, a frame the same size as the 
flask is placed around the body of sand and a weight 
is placed on top to prevent straining the mold when 
under pressure. 

Small flasks up to^ 14 in. square may best be made 
of iron, without bars in the cope. Those larger maj, be 
of either wood or iron to suit the style of work to be 
put in the flask. When the flask is for a special pattern 
and is to be used for that only, an iron flask will give 
the better service and is far cheaper. When for general 
patterns, the wood flask has many advantages. The 
bars may be fitted to a pattern in wood with little time 
or expense, and for a class of small work up to 40 in. 
square, may be made of suflicient strength. Larger 
flasks are made of wood having bolts or iron bars for 
stiffening the cope. When but a single casting is de- 
sired, even to very large castings, the flask mav be 
more cheaply made with a wood frame and iron bars 
than entirely of iron. 

In manufacturing shops having a fixed line of pat- 
terns, the iron flask is of great value. The first cost is 
more than that of a wood flask, but the durability far ex- 
ceeds that of wood. The bars are shaped to suit the pat- 
tern, and they remain so ; while a wood bar burns out and 
the joint of the wood flask burns away leaving holes 
which may cause a run-out, thus losing the casting. The 
iron flask is much heavier to handle, but it mav be fitted 



8 FOUNDRY PRACTICE 

so as to require less anchoring in the sand, as gaggers 
and soldiers which would be required in a wood flask; 
thus the time saved in molding will more than ecjual 
the extra help necessary to handle the flask. Large 
flasks to hold castings as cylinders, engine girders, bed 
castings, etc., and flasks to be used many times, should 
be made of iron and well braced. They are then readv 
at all times and may be used without loss of time in 
repairs. 

To point out the saving resulting from the use of a 
flask instead of bedding the pattern into the pit, the 
relative time recjuired for making a girder casting 
in the two ways may be cited. Before the flask was 
made to hold the pattern, it was bedded into the pit with 
a cope to cover it. It required a time equivalent of 14 
days, with a molder and helper to complete and cast 
the mold. After the flask was made so the pattern was 
rammed in the drag and turned over, it required a time 
equivalent of 9 days for a molder and helper to make 
the same casting. 

Holders' tools vary greatly with the general type of 
work that the molder is making. The number of tools 
necessary for a molder on a particular type of work 
may be three or four, while on intricate work manv tools 
may be required. There are tool manufacturers who 
can furnish tools of nearly any size or shape that a 
molder may desire. The more common forms are shown 
in Fig. 2. These are used for nearly all classes of work 
and are made in many sizes as desired. No. i is a round 
point finishing trowel; No. 2, a square trowel. No. 3 
is a lifter for removing sand from deep and narrow 
parts of a mold. No. 4 is a flange and bead tool for 
slicking special round surfaces. Nos. 5 and 6 are two 



FOUNDRY PRACTICE 9 

forms of double-end slickers which represent the genera; 
forms out of greatly varying forms of such tools. No. 
5 has an oval slick at one end with the spoon slick at 
the other. No. 6 has the square and heart slicks. Xos. 
7, 8, and 9 shoAv corner slicks of wdiich No. 7 is for 
round corners. No. 8 for square, and No. 9 for inside 
corners. Nos. 10 and 11 are pipe slicks for cylindrical 
surfaces. No. 10 has the square ends, while No. 11 has 
the safe end for a corner slick. 




Fig. 2. 



The success of making the mold and obtaining a 

good casting is dependent mainly upon the manner of 

ramming the sand to form the mold. Hard spots in 
the sand cause scabs, and soft spots, a swell. Uneven- 

ness of ramming causes similar unevenness in the cast- 
ing. 

In rammino^ the drao-, the flask should be filled 



lo FOUNDRY PRACTICE 

to a depth of from 5 to 6 inches, ramming first around 
the edge of the flask, then next to the pattern, and, 
lastly, the portion between, using the pein. On small 
castings, it is rarely necessary to ram the sand over the 
pattern. The pein or the butt of the rammer should 
never strike within an inch of the pattern, as it will 
cause a hard spot at that point. 

In deep molds, the succeeding rammings should be 
done by filling in loose sand to the depth of about 6 
inches, and ramming first with the pein then with the 
butt in order to give the mold the proper degree of hard- 
ness. 

In ramming the drag, either the pein or the butt may 
be used as soon as the pattern is well covered so that the 
ramming is not near the pattern. It is of advantage to 
tramp the sand with the feet before butting, as that 
more quickly compresses it to a moderate hardness and 
facilitates the butt ramming. 

In ramming the rim of a pulley, the rammer should 
be directed away from the pattern to prevent scabbing 
the rim. 

The larger the pattern, the harder the sand may 
be rammed. When of a depth to give a great pressure 
on the bottom, the sand must be rammed harder to hold 
the pressure and prevent the cracking of the surface 
causing roughness sometimes called "whiskers." 

On patterns of the round column type, the sand may 
be rammed very much harder than in other cases, if the 
metal is to be thick. It is very imp'^rtrmt to have these 
rammed evenly, as unevenness will cause defects in the 
casting, even though it is not of a hardness at any 
point which would be detrimental were the entire mold 
of that hardness. 

The softer the sand can be left an 1 still hold the 



FOUNDRY PRAC'liCE ii 

casting in proper form, the less is the HabiUty of losing 
the casting. The sand must be hard enough to hold its 
shape, but after that the risk of loss in casting is in- 
creased as the hirdness is incre:;sed. 

In ramming the cope where there are no bars, the 
sand is filled in to a depth of about 6 in. and rammed 
around inside the flask, then the remaining portion is 
rammed evenly with the pein. The butt should not be 
used in the cope until the entire flask is filled, then the last 
ramming on top is done with the butt. If the butt is 
used before this, it causes a hard surface so that the 
sand does not unite in the succeeding ramming and is 
lial^le to fall out when the cope is turned over. When 
the cope has bars, each division enclosed by the bars 
is rammed separately as a small cope, but all the divis- 
ions must be of an even hardness. The successive ram- 
mings are made by filling in about 6 in. at a time and 
ramming with the pein. 

The proper manner of holding the floor rammer 
while ramming is to grip the rod connecting the pein 
and butt with one hand above the other. Never hold 
the rammer with one hand on top of the upper end of 
the rammer, as it will jar the operator and it is harder to 
do good ramming while in this position. 

The proper venting of a mold is of as great impor- 
tance as any part of the process. If at any point the 
venting is insuflicient to carry off the gases, the metal 
will blo'w and spoil the casting. 

The air in the mold, when the metal is being poured, 
must be able to escape. This is provided for in some 
cases by the riser, but often the vents are depended upon 
for this purpose. The water in the sand is heated to 
steam and must escape through the sand. The contin- 



12 FOUNDRY PRACTICE 

lied addition of sea coal in the facing and tiour and 
plumbago in the mold increases the formation of g-ases 
when the metal comes in contact with the face of the 
mold. If these can not escape into the sand, they force 
an opening through the molten metal which is known 
as blowing. To enable the gases to pass through the 
sand, the mold must be properly vented. Some sands 
are so coarse and open that they require much less 
venting than others which are fine and close in textiu'e. 

Small and thin castings, rammed lightly, require no 
venting. In casting- heavy, thick plates the drag must 
be well vented, but the cope does not require much vent- 
ing, although it is always best to A^ent it. In venting 
any plain casting, the size of vent wire is mainlv depend- 
ent upon the depth of sand tO' be vented. For flasks 
up to 12 in. in depth, Vg in. wire serves well. The 
exact size of wire used is unimportant, so that the vent- 
ing is close enough to give free escape of the gases. 
The vent wire should not strike the pattern or scrape 
along a side, as it forms holes that the metal mav flow 
through and allows the metal to stop up the vent, which 
gives the same condition as though there were no vent. 
The bottom board should be put on the drag and 
rubbed to a bearing, then removed, and the surface 
creased crosswise by striking with the corner of a stick 
to reach the width of the drag, then the drag vented 
The creases form openings through which the gases 
may escape when the drag is turned over. 

For small castings, the cope should be vented through 
almost to the pattern to give free escape for the gases 
and air. For larger castings it is often advisable to 
leave a layer of 2 to 3 inches next to the pattern with- 
out vents. This does not give free escape for the air ; 



FOUNDRY PRACTICE 15 

thus a pressure can be maintained within the mold while 
pouring which prevents the drawing down of the cope, 

]Many molds have enclosed bodies of sand which do 
not have free vent connections with the top or bottom 
of the flask, as anchors in pulley molds, center parts 
in three-part flasks, or large green sand cores. The 
vent must be led to some convenient point where an 
opening is left through the cope for the gases to escape. 
A gutter may be cut around the surface of the body of 
sand about 3 or 4 inches from the pattern and connected 
to the vent opening. Slant vents from the gutter will 
give free vent to the gases. 

In some molds there are pockets having metal on all 
sides but one. The vent must be led away through this 
side and this very freely. When the pocket is small, 
a vent rod may be laid in it, and slant vents leading to 
the pattern give the necessary relief. When the pocket 
is of large size, it is not safe to depend on the slanting 
vent. In these cases the gases are collected by a coke 
or cinder bed laid in the pocket and led to- the outside 
by a vent pipe or large vent rod. 

In some patterns, as columns, the vent mav be led 
off at the parting instead of through the bottom of the 
drag. After the flask is rammed up and the cope re- 
moved, vents are made under the pattern from the sur- 
face of the drag at a distance of about 2 inches apart^ 
These are led to the outside by cutting or scratching a 
small gutter in the surface from the vent to the flask. 

Pit molds and all floor molds must be provided with 
a cinder bed located about i^^ or 2 feet below the cast- 
ing to provide for the escape of the gases of the lower 
half of the mold. The cinder bed is connected to the 
surface by vent pipes which give free passage for the 



14 FOUNDRY PRACTICE 

gases. Very deep molds may have cinder beds locatcrl 
at different levels around the mold. The gases are 
led to the cinder bed by freely venting the mold so that 
the wire strikes the bed. 

Surface molds require much better venting than 
those covered with a cope, as the metal gives no pres- 
sure except its weight ; thus it can not force the gases 
against much resistance. Small surface molds may not 
require venting, if the sand is rammed only enougli to 
prevent the metal cutting when poured. Larger molds 
must be provided with a cinder bed and well vented 
from the mold and to- the surface. 

When two parts of a flask are to be lifted apart after 
the sand is rammed, it is necessary to make the surface 
at the parting so that the two bodies of sand will not 
knit together but separate freely when the flask is 
opened. In order to ensure the parting, the surface of 
the sand must be slicked smooth after making the sur- 
face harder than the other part of the mold and cov- 
ered with a parting sand. 

When the drag is turned over and the follow board 
is removed, the surface is gone over with the hand and 
sand tucked in wherever soft spots are found. The 
sand is then cut away to the parting of the pattern or 
to the surface of the part. A thin coat of sand is then 
riddled onto this surface and the whole slicked to a 
smooth face. The additional sand compacts the surface 
to a harder shell and should not be easily broken by the 
ramming oi the sand that rests on this parting. This 
slicking must not be carried to an extent of causing an 
extra hard or bricklike face, as this will cause defective 
castings similar to hard spots in ramming. 

Parting sand is put over the surface in a thin coat- 



FOUNDRY PRACTICE 15 

ing. All parts of the sand mvist be covered, for any 
spots left bare will stick and not give a clean part. 
Parting sand used for this purpose may be any fine dry 
sharp sand, very fine cinders, or burnt core sand from 
the burned cores in the castings. This sand is most 
convenient on all plane surfaces and where the slope 
IS not so great that it will not stay on the entire face. 
In cases where the dry sand will not cover the surface 
well, wet sharp sand makes a good part. The fine sharp 
sand is dampened until the sand sticks together, then it 
is put onto the surface with the hand or slicked on with 
a tool. It often helps to dust a little dry parting sand 
over the wet sand after it is on the surface, as the wet 
sand sometimes sticks when the surfaces are lifted 
apart. 

Parting sand and burnt core sand make molding 
sand coarse and weak as it loses its strength to hold a 
form when rammed. Too much of the parting sand will 
spoil the sand for the mold. 

Gates are the openings through w^hich the metal en- 
ters the mold. The location of the s^ate makes a gfreat 
difference in the resulting casting. A mechanic can 
show his ability in gating properly more readilv than 
in any other part of the mold. Many castings are lost 
just because the molder is not particular enough in 
locating and cutting his gates. 

All plain castings having about an even thickness, 
and that greater than the runners, are gated at the side 
and present little or no difficulty. As thin plates having 
runners heavier than the casting set sooner than the 
runner, they can not be gated at the side because when 
the runner cools the casting will be strained or warped. 
A good form of gate in such cases is that known as the 



i6 FOUNDRY PRACTICE 

bridge gate, having a basin above which is connected 
to the mold by a long narrow opening through which 
the metal enters. This gate is easily broken off and 
leaves the casting straight. 

On anv casting having ribs running from the side 
to the bottom, the metal should be directed lengthwise 
of the rib, in preference to flowing over the edge of the 
sand, as there will be less danger of the metal cutting 
the sand. 

The thin parts of a casting should be filled as quickly 
as possible after the metal starts into them. A casting 
having heavy and light parts should be gated so that 
the thin parts can be filled quickly, and not rise slowly, 
as when filling both the heavy and light parts at the 
same time. If the gate is placed on a thin part so' that 
the metal flows over the surface of the mold into the 
heavy portion of the casting, the inflowing metal will 
become cooled and as it rises into the thinner parts it 
is liable to become cold-shot or form seams, which 
spoils the casting. 

The gate must be so located that the metal will not 
flow over a sharp bead of sand which may be washed 
away. This difficulty is sometimes overcome by use 
of the horn gate. 

The common use of a riser on small castings is to 
allow the air and gases to pass out of the mold while 
it is being poured. The dirt carried into the mold by 
the inflow of metal is carried on the surface of the iron, 
and, as the metal rises in the riser, the dirt is floated out 
of the casting. 

On large castings or those whose shrinkage is great, 
the riser is made large so as to supply metal to feed 
the shrinkage. The riser nmst be large enough so that 



FOUNDRY PRACTICE 17 

it will not freeze until the casting itself has set. If 
the shrinkage is not thus taken care of, the casting is 
liable tO' have shrink-holes in it. 

The location of the riser for small castings is not of 
so great importance, although it is best to have it where 
the dirt is most liable to accumulate. In castings where 
it acts as a feeder, it should be connected as near as pos- 
sibfe to the heaviest part of the casting. In castings of 
such a size as to require feeding, the riser is placed over 
the heaviest part of the casting and it becomes a feed- 
ing head. In this case the casting is fed by a feeding 
rod which keeps the riser from freezing until the casting 
sets. This process is called feeding, or churning, the 
casting. In some cases, as cannons, or rolls which are 
cast on end, the casting is made longer than that de- 
sired and the end turned off in the lathe. The extra 
length takes the place of the feeding head and is known 
as a sinking head. In this case the casting does not re~ 
quire feeding. 

Some foundries making castings only up to the me- 
dium weight never make use of the feeding rod but, 
instead, depend on the riser as a sinking head and pour 
the iron as dull as it can be run into the mold. These 
castings are often unsatisfactory and frequently have 
shrink-holes in their upper surface. 

A skim gate is an arrangement of gates, risers, and 
runners leading to a mold, whereby a supplv of pure 
metal may be obtained, and the impurities remain in 
the riser. An ordinary skim gate may be constructed 
as in Fig. 3. The molten metal enters through the pour- 
ing gate a and flows through the runner c into the riser 
b. The impurities come to the top in the riser while 
the pure metal, being heavier, remams at the bottom and 



i8 



FOUNDRY PRACTICE 



flows out through the runner d into the mold c. The 
arrangement of the gate, runner, and riser, as shown 
in the plan view, is for the purpose of giving the metal 
a rotary motion while rising in the riser b. This is 
intended to aid the separation of the impure metal, 
sand, and dirt from the pure metal. The runner d is be- 
low the level of the runner c. The eross section of c 



Q [Cope^:,'j 






. X /. 



bp^ 



d 



e 



FiL 



must be greater than that of d to ensure keeping the 
riser b full while the metal is being poured. Good re- 
sults and sound castings are obtained by the use of this 
arrangement for the gate. 

The top gate with the pouring" basin shown in Fig. 
47 forms a good skimming gate. It is upon the prin- 
ciple that the pure metal being heavier flows into the 
mold from the bottom of the basin, while the impurities 



FOUNDRY PRACTICE 



IQ 



remain at the top. In pouring, the hasin must be kept 
full so that the metal enters the gate from the bottom 
instead of from the surface of the metal in the basin. 
The onlv chance for dirt to be carried into the mold is 
when the metal first starts before the basin is full and 
forces sand and dirt into the mold. 

The preceding arrangements are formed by the gate 
sticks, ofate cutter, and trowel. A verv convenient de- 





vice for forming a skim gate is by use of a pattern as 
shown in Fig. 4. This pattern is rammed up in the 
drag with the pattern to be molded. The portion marked 
A is a core print. After drawing the pattern, the core 
B is placed in the prints. The metal entering at C is 
given a rotary motion under the riser placed at D where 
the impurities rise. The pure metal flows under the core 
into the mold through E. 



20 FOUNDRY PRACTICE 

There are few things in connection with making a 
mold that are of greater importance than the construc- 
tion of the pourmg basin, gate, runner, and riser. Skill 
is necessary to be thoroughly successful in their con- 
struction. In these, the washing or cutting away of 
the sand by the force of the falling metal is most likely 
to occur. When this takes place, great damage is likely 
to result to the casting. If the molder should slight 
any other portion of the mold, he may still get a cast- 
ing which v/oiild pass inspection ; but any neglect or 
ignorance in the construction of the pouring basin, gates, 
or runners will usually spoil the casting. When the 
sand in these cuts or breaks, the loose sand flows with 
the metal into the mold and causes a dirty casting- 
Great care should be taken to have the sand well tem- 
pered for the construction of a pouring basin. To make 
a reliable pouring basin, the sand should be rammed 
evenly intO' the box or frame, and the basin cut out w^ith 
the trowel. This ensures an even solidity to the sand 
and prevents cutting or washing. 

Gaggers are L-shaped irons used by molders to an- 
chor the sand into the flask. The lower end of the 
gagger is called the "heel," and varies in length from 
2 to 6 inches to suit dififerent conditions. The other 
portion of the gagger may be of any length to suit 
the depth of flask in which it is used. Some gaggers 
are made with a short hook bent at the upper end for 
hooking over the bar of the cope to ensure firmness in 
lifting. They are made either of wrought or cast iron. 
Wrought iron is preferable, for in some places it is 
necessary to bend the gagger to suit the particular con- 
ditions. 

Gaggers are of great assistance in securing sand into 



FOUNDRY PRACTICE 21 

a flask and in many cases are indispensable. To ob- 
tain a good lift in a cope without gaggers, requires the 
bars to be in very good condition and to come near to the 
parting. With gaggers, the sand may be anchored with- 
out the bars being new for each special casting. 

The strength with which the gaggers hold the sand 
depends upon the manner in which they are set. When 
properly set they hold with great efificienc}^ When set 
wrongly they only add weight tending to pull the sand 
down or cause a drop-out. 

The gagger should be so placed that the heel comes 
near to the parting of the sand to be lifted and should 
be parallel to it. The length of the gagger should come 
against the bar or frame of the flask as shown at A 
in Fig. 29, page 68. It is not always necessary to have 
the gagger stand vertical, although that is the best 
position. Odd slopes may often be accommodated bv 
slanting the gagger or bending the heel. Oftentimes 
mistakes are made in setting gaggers improperly and 
cause trouble. A few^ ways of setting gaggers so they 
do not hold as desired are shown in Fig. 29. At B 
the gagger will hold the sand above all right, but the 
sand below is liable to drop. In this cope the desired 
end could be accomplished by placing the gagger against 
the bar at right angles and have the heel parallel to the 
face of the slope. At C the heel comes onto the slope 
rightlv, but the length of the gagger does not come 
against a bar, therefore it does not hold anything. In 
almost every case the gagger would drop down when the 
cope is lifted off. At D the gagger is placed at a slight 
slope to the bar and its heel parallel with the parting. 
This will usually hold quite well, but is not strong nor 
a good way to set the gagger. The holding power de- 



22 FOUNDRY PRACriCE 

pends upon the sand pressing the gagger against the bar 
firmly and compressing closely around it. Another mis- 
take sometimes made in setting gaggers is to have several 
located in a corner against one another and the heels 
radiating in different directions to hold in a difftcult 
place. The sand can not compress around all the gaggers 
or hold them firmly together. Part of them are .held 
only by the friction of one on the other, which is ni- 
sufBcient, and will drop out. 

The number of gaggers needed is dependent upon 
the sand used and the width and depth of the body 
of sand lifted. When holding a corner or edge of sand 
by a gagger, have the gagger as near as possible to the 
edge and parallel with it. Always be sure the gagger 
IS covered with at least a thin coating- of sand. If not, 
the iron is liable to cause an explosion when coming 
in contact with the wet rust. Before setting in the 
sand, the heel of the gagger must be wet in clav wash 
or flour paste. Otherwise the sand will not stick to it. 
Have at least two^thirds of the length of the gagger 
come against the bar, and have the gagger as long as 
the cope will allow. 

Soldiers are wooden strips or pieces placed in the 
sand to anchor the body together. They are made of 
size, length, and shape to suit the case w^iere it is to 
be used. Oftentimes soldiers are placed beside bars 
to hold hanging bodies of sand, instead of having special 
bars. 

The holding power of soldiers is much greater than 
that of rods or nails as the sand packs against their un- 
even surface and will not give without tearing up the 
entire body of sand. This will be fully appreciated if 
you try to pull a soldier out after it is rammed into the 



FOUNDRY PRACTICE 23 

sand. The customary use is for holding small bodies of 
sand that can not be held by gaggers. It is not neces- 
sary to have the soldier come against a bar. It holds 
firmly when in the body of the sand itself. 

In setting soldiers, they should have the lower end 
wet in clay wash and pressed dow^n to place in the sand 
before ramming. The sand should be in a loose coat- 
ing of about one inch over the parting to be soldiered, 
then when the soldier is placed, some sand will remain 
below the wood, but there should not be a thick coating 
that ma}' fall away after the pattern is removed. The 
main precaution is to be sure that the wood is covered by 
sand and not have that coating such that it mav fall 
away and expose the soldier. In case the soldier is 
exposed to the mold, the molten metal will ignite the 
wood, giving gases that can not escape fast enough, thus 
causing the metal to blow. This sometimes throws the 
metal for a great distance, endangering the safetv of 
the men near by. Even a very thin coat of sand will 
prevent the blowing from the soldier. 

The points or corners of a mold are usually held by 
nails or rods. AA hen the body of sand conies under the 
pattern, the nails or rods are set similarly to soldiers and 
rammed into the sand. When the pattern is liable to 
tear in drawing or a body of sand is not strong in itself, 
it should be well nailed when being rammed. 

Green sand cores which are exposed at the parting 
may best be nailed after the flask is rammed,* for then 
the nail head supports the surface of the sand while 
the nail strengthens the entire bod\ of the core. When- 
ever there is doub. of the strength of a corner or core, 
be sure to secure well by nails. 

Where the mold is of such shape as to endanger 



24 FOUNDRY PRACTICE 

the metal cutting at any point, the part should be well 
nailed after the pattern is removed, leaving the heads 
of the nails exposed. A few nails placed where a cor- 
ner or surface is liable to cut or wash by the inflowing 
metal will prevent the washing away of the sand and will 
secure the surface in a surprising degree. 

Rods are often rammed in the sand to strengthen 
and bind a body of sand that must resist a pressure 
from the metal. Any large green sand core must be 
well rodded to give the mass strength and firmness. 
When the surface of a green sand mold must resist 
strong pressure of the metal, the sand must be well 
tied together with rods. In a pit mold for fly wheels, the 
head in the risers gives a head on the sand of from 
2 ft. to 4 ft., which means a pressure per sq. in. of from 
8 tO' 14 pounds. This is resisted by rods laid close to- 
gether in the sand when the mold is rammed. In pockets 
having metal under a portion of them, giving a strong 
lifting pressure, rods are laid in to take up the strain 
and secure the pocket firmly. 

A molder's skill is shown in his ability to patch 
a mold, much more than in any other part of his trade. 
In some cases patching and botching are synonymous, 
but with a good molder the latter is not known. Manv 
patterns cannot be removed from the sand without more 
or less tearing of the mold, and niany old patterns are 
used that an unskilled man would think it impossible to 
get a good casting from. A good molder will be able 
to repair a mold that seems almost completely ruined 
when the pattern is removed, and to get as good a cast 
ing as though the pattern were perfect and he secured a 
good draw ; the difference being mainly in the time nee- 
essarv to finish the mold. 



FOUNDRY PRACTICE 25 

Practice and experience with different cases and con- 
ditions can alone fit a man to cope with cases requiring 
much patching, but we can offer a few suggestions that 
may be helpful to the beginner. When the sand is dry 
or of the proper temper for the main body of the mold, 
it is nearly impossible to patch the sand at corners 01 
difficult places. To' begin, then, the part to be patched 
should be dampened with the swab, being careful not 
to wet the sand so as tO' cause the casting to blow. In 
patching a corner, place a tool or a straight face against 
one side and press the sand in at the other. A good 
corner can not be made with a single tool alone. Sand 
pressed on with the fingers may be added to and will 
hold firmly. When put on with a trowel, a surface is 
made which will not unite well with the sand put on af- 
terwards. Patching done with the fingers will not cause 
a scab on the casting, but slicking a patch may act 
similarly to being rammed too hard at that point. Where 
much is to be put on, put nails in the place tO' be patched 
so the heads will come a little below the finished sur- 
face. The nails help to hold the sand while putting it on 
and secure the patch after it is finished. Whenever 
the patched part is quite large, it "^hould be well nailed 
after finishing, so that the heads come flush w^th the 
surface. In patching down in a mold, sand may be put 
on by pressing small balls of sand onto a tool so that it 
will carry its weight, then lowered to the desired place 
and lightly slicked on. 

In finishing the mold, the entire surface must be 
closely examined to be sure that it conforms to the cast- 
ing desired. The loose sand at the edges must be 
pressed back to place or removed so that it will noi 
fall into the mold when the flask is closed, thus causing 



26 FOUNDRY PRACTICE 

a dirty casting. All loose sand in the path of the in- 
flowing metal must be removed. Be sure the runners 
are so that the sand will not wash when pouring the 
mold. 

The last thing before closing a mold, a molder should 
see that all loose sand is removed and the mold is clean. 
If portions of the mold are dark, light may be thrown 
m by a small hand mirror which may be turned so avS 
to light the desired parts. 

'Thin and weak patterns have, oftentimes, to be 
strengthened by pieces which are stopped off in the 
mold, leaving the desired shape of casting. Where a 
pattern is uniform throughout its section and casting=^. 
are desired of dilTerent lengths, a pattern is made for 
the greatest length and the mold is stopped off to the 
desired length for the casting. 

In stopping oTf strengthening pieces, the face of the 
sand in the part to be filled is cut up with a tool, then 
filled with sand and tucked with the fingers. Fill in 
small amounts at a time so the sand will be of the same 
hardness as other parts of the mold. When within 
about Yi in. of the finished surface, the part should be 
well vented through the sand. The finished face is 
slicked with the trowel, being careful not to get the 
face too hard. 

When stopping oft* a portion of the pattern, a stop- 
off piece which conforms to the prittern at that point is 
laid in and the end formed to the piece. When without 
a stop-oft' piece, the end is formed by a trowel or a 
piece of wood and the sand filled in to close that part of 
the meld. 

The face of the sand should .'ilways be cut so the 
sand pressed onto it will unite and hold firmly. WTien 



FOUNDRY PRACTICE 27 

the metal is not to cover the face made in the stopping- 
off, it is not necessary to- vent the sand nor to be s'> 
particular in obtaining an even hardness ; but it is al- 
ways advisable to be as careful with this as in cases 
that are more particular. 

When a mold is filled, the metal freezes at the sur- 
face first. The bottom solidifies before any other part, 
then the other surfaces where the heat is most readily 
carried off. This solid surface gives a fixed form which 
resists any force tending to change its shape. As the 
metal shrinks upon solidifying, something must replace 
this shrinkage. After the outside surface is set, the metal 
is drawn from the still molten centre of the casting to 
rcplcice the shrinkage. This gives a porous, honey- 
combed, or rotten centre which has no strength. This 
defective condition is prevented by feeding hot iron 
to' tlie centre of the casting while it is solidifying to 
replace this shrinkage. 

There are two sfeneral methods of feeding a castine: 
first, using a sinking head ; second, feeding bv use ot 
a feeding rod. x\ sinking head is where the mold, when 
standing in a vertical position, is made longer than the 
desired casting and of the same size. The excess length 
is filled with metal and allowed to sink to replace the 
shrinkage of the casting below. This excess is turned 
ofT, giving the solid casting. To greatly reduce the 
work of turning ofi: a large part of a casting, the feed- 
ing head is made much smaller than the casting and 
kept open by means of a feeding rod. 

The feeding. head must always be large enough to 
enable it to be kept open until the casting below has set. 
When the feeding head is small, it freezes almost before 
a rod can be inserted, hence does not accomplish the 



28 ■ FOUNDRY PRACTICE 

purpose. It is always safe to expect that some of the 
metal will freeze to the sides of the feeder all the time, 
even if the metal is kept in motion constantly ; hence 
the feeder must be increased to allow for this in pro- 
portion to the time that it should be kept open. A feed- 
ing rod can not be used to advantage in a feeder less than 
3 in. in diameter. This can be kept open only a short 
time, hence becomes ineffective where the casting be- 
low recjuires quite a time to solidify. Where a large 
feeder can not be used, due to bars or to conditions that 
can not be avoided, a small one may be made to keep 
open longer by increasing its length and supplying hot 
iron to heat this portion above that of the casting. 

A large riser or feeder may have a much smaller 
opening intO' the casting and still be as effective. A 
3-in. feeder may have an opening into the casting 11-2 
in. in diameter and give as good results as though the 
full size of the feeder were opened through. This 
allows the use of a much larger feeder and still its re- 
moval from the casting as easily as the smaller one. The 
smaller opening is kept from freezing b}' use of the 
feeding rod. 

The rod should be heated in the ladle before lowering 
into the feeder, to prevent chilling the iron. It should 
be lowered slowly into the mold until the bottom is 
touched, then lifted 2 or 3 inches and given an up 
and down motion. Due to this motion it is commonly 
called ''pumping," or "churning," a casting. The feed 
rod should not strike the bottom of the mold, as it is 
liable to punch a hole in the mold, causing a bunch on 
the casting. The rod should be held at one side of 
the centre and moved around to keep as large ?n open- 
ing as possible at the entrance of the feeder into the 



FOUNDRY PRACTICE 29 

casting. A casting properly fed will freeze from the 
bottom and slowly crowd the feed rod out of the casting 
until at last it is only in the riser. 

The job of feeding a casting is not a pleasant one. 
The direct radiation from the metal and the burning 
gases about the flask make it very hot and disagreeable 
work. For this reason, many molders will freeze up a 
riser long before the casting below^ has set. It is very 
marked that often in feeding a number of the same cast- 
ings, poured at the same time, part of the men will 
have their feeders frozen long before the others do. 
Those who froze theirs first have castings the same on 
the surface as the others, but the centres would be very 
different were the castings cut open. The man keeping 
his feeder open the longest has the strongest and most 
solid casting. 

The size of the rod used is unimportant except when 
it is so large that it closes up the feeder rather than 
keeping it open. In a feeder smaller than 3 in., the 
feeding rod should be 34-i"- For larger feeders, the rod 
may be increased. A 3/g-in. rod is most commonly used, 
as larger ones become too heavy to handle without quick- 
Iv tiring the workman. 

The proper setting and venting of cores is an im- 
portant factor in molding. Cores are made of sand with 
binders which, when dry, form a solid mass of the desired 
shape. They are placed in a mold to make the casting 
different, in part, from the pattern. When burned by. 
the molten metal, the core crumbles and leaves the 
casting hollow in that part. The core may be made 
to form recesses in the casting, or holes of desired shape 
through the casting, or to hollow out the inside of the 
casting. 



30 FOUNDRY PRACTICE 

The binders which hold the sand together in the core, 
the entrained gases of the new sand, and other con- 
stitncnts of the core burn out forming a volume of gas 
that must be allowed to escape when the metal comes 
in contact with the core. If the gases are not properly 
carried off, they force their w-ay through the easiest 
relief, which may be through the molten metal, causing 
blowing ; this spoils the casting, making the bodv 
spongy, if not blowing nearly all tlie metal out of that 
portion of the mold. 

When a core is made, vents are always provided to 
carry the gases to some particular points where they 
may be conducted away through the sand of the mold. 
A core completely surrounded with metal, except at 
its vent, must be well provided with free passage for 
the gases. Cores having the metal only on one face, as 
slab cores covering a plane surface, do not require 
special venting, as the sand will carry off the gases 
freely enough. Small cores partly surrounded wath 
metal do not require special venting, as the sand will 
be sufficient to take up the small amount of gases given 
off. 

Where prints are provided on the pattern for simple 
cores, the setting of the core is a simple matter. The 
vent must be provided for, then the core is lowered into 
the print recess which anchors the core in the desired 
position. Round cores having a print at both ends 
must be set into the drag so as to enter the print of 
the cope without tearing up the top of the mold. This 
can be done by the eye in lining it from dift'erent direc- 
tions, being sure that it is directed vertically. Horizontal 
cores have the print of both ends to rest the core on. 
The cores thus far considered are held in position bv 
the print recess in the mold. • 



FOUNDRY PRACTICE 31 

j\lanv forms of cores have prints for locating the 
core, but nothing to hold the core from floating when 
the metal is poured into the mold. Small cores, as those 
for making a hole in a depressed lug, may be anchore I 
by placing nails slantwise into the sand to bear against 
the core. 

Large cores resting in the drag are held down by 
means of chaplets, as considered under the setting of 
chaplets, pages 34-36. 

Many cores have no print in the drag but have one 
in the cope. In such cases the cores are anchored in 
the cope by wires so as to hold their weight before the 
mold is poured ; then when the metal tends to float the 
core, the sand bears the stress. In green sand copes, the 
core may be anchored bv running a soft iron wire from 
the loop in the core to the top of the cope, then fas- 
tening firmly to a cross bar or to a rod resting on the 
cope bars. In dry sand copes having heavy cores, 
the cores are often bolted to cross beams by bolts hav- 
ing a hook to enter the loop in the core. 

Cores are sometimes of such form or weight as to 
recjuire straps for lowering them into the mold. Heavy 
cores may be set by a crane, when straps are used, which 
bend easily to prevent tearing the sand when being re- 
moved from the mold. 

Chaplets are used for anchoring cores into a mold 
when the cores are of such shape that they are not prop- 
erly supported by the sand. The forms and types of 
these chaplets vary greatly. The two main types are the 
single-headed and the double-headed chaplets, as shown 
in Fig. 5. The simple form of single-headed chaplet 
is shown at a. This has the forged head, having burrs at 
N to secure the chaplet more firmly in the metal. The 



32 



FOUNDRY PRACTICE 







n 





cn 




Figr. S. 



FOUNDRY PRACTICE 33 

end may be sharp or blunt, to suit the place where it 
is to be used, b shows a stem on which a head of de- 
sired size and shape may be riveted, d shows the double- 
end forged chaplet. These are made of any desired 
length between outside faces varying by ^/jq of an inch, 
c is a stem for a double-headed chaplet. Any size or 
form of head may be riveted on to suit particular cases. 
e shows a double-end chaplet and nail. The nail holds 
the chaplet in position before the core rests on it. This 
assists in setting in some cases. The one shown has 
riveted heads making use of a stem on which the de- 
sired heads are placed. / gives a form of chaplet made 
of cast iron. This is a cheap double-end chaplet which 
may be made where it is used, g shows an adjustable 
double-end chaplet. It is threaded into both heads with 
the stem threaded to allow the adjustment. The chap- 
let and stand are shown at h. This enables quick ad- 
justment of chaplets, as the stand is rammed in the drag 
against the pattern ; hence the chaplet may be dropped 
into place when the pattern is removed. A form of 
spring chaplet shown at / may be used to substitute for 
a double-headed chaplet and springs to give the desired 
distance between faces. 

The most common forms of chaplets are those shown 
at 0, b, c, and d. There are firms making these of all 
sizes and shapes. They may be purchased at a lower 
cost than they could be made without the use of special 
machinery. 

In using chaplets, a few precautions should be ob- 
served. Chaplets placed in a mold weaken the resuking 
casting in a greater or less degree. It is always prefer- 
able to avoid their use where possible. They weaken the 
casting : first, by introducing a foreign metal into casting, 



34 FOUNDRY PRACTICE 

thus destroying the uniformity of the metal; second, by 
forming blow-holes or porous metal about chaplet ; and 
third, by failing to unite with the metal, thus becoming" 
loose or leaving a hole in the casting. These evils may 
be greatly reduced by proper design and use. The first 
cannot be avoided, but may be made small by using chap- 
lets of proper size and shape to cause the least possible 
break in the uniformity of the metal. The second may 
be nearly always avoided by proper care in regard to the 
condition of the surface of the chaplet. Moisture on the 
chaplet holds the metal away, causing blow-holes. Rust 
makes the metal boil and blow, causing porous metal to 
form. The coating on the chaplet must be such that the 
iron will unite with it and lie quiet. Red lead put on 
with benzine makes a good coating. A tinned surface 
gives the best satisfaction for this purpose. 

The third evil may be avoided by so shaping the 
chaplet that the metal will adhere closely and bind itself 
to the chaplet. This may be done by having notches or 
depressions in the stem as shown at c, Fig. 5, or by barbs 
or burrs, as N on a. In some cases the thickness of the 
metal where the chaplet is placed is not sufficient to en- 
sure a firm hold on the chaplet. The thickness should 
be increased around the chaplet by cutting away the sand, 
forming a button having the chaplet in its centre. 

The efifective strength or holding power of a chaplet 
is dependent upon the way it is set in the mold and the 
manner of wedging it after the flask is clamped. Alany 
castings are lost, due to improper setting of the chaplets. 
The chaplet must have a firm bearing on the core and 
the pressure it is to resist must act directly against its 
length. When so placed that the pressure tends to move 



I 



FOUNDRY PRACTICE 



35 



it sidewise, the resisting power is only that of the sand 
around the chaplet. 

The chaplets set in the drag must come to a bearing 
where it is to reniain. Those in the cope extend through 
and are held against the core by w^edges or weights from 
above. Where the flask has a bottom board, the chaplets 
set in the drag may be pointed and driven into the bot- 




F\g. 6. 

tom board as shown at a and d. Fig 6. The head of the 
chaplet should conform to the shape of the core. If the 
head is not shaped the same as the core at the point of 
bearing, the chaplet may cut into the core, thus not hold- 
ing it in the proper position, or the bearing may be on 
one side of the chaplet, which, may tip it over. Where 
the sand is very deep below the point where the chaplet is 



36 FOUNDRY PRACTICE 

to be placed, or there is no bottom board to drive the 
chaplet into, a block may be ramm.ed into the sand as at 
the base of c. The chaplet must be set vertical, for, if 
slanting, the effect will be that shown at c. This chaplet 
has bearing only at the edge and will hold but little, as 
the sand will crush beside the chaplet, allowing the core 
to move. Where many chaplets of the same length are 
to be set, as in duplicate work, much time may be saved 
by ramming in the mold the chaplet stand shown at b. 
When the pattern is removed, the chaplet may be placed 
in the stand, thus saving the adjustment of height and 
driving to a firm bearing as required in previous cases. 
There are many other conditions to be considered in 
setting chaplets in the cope. It is best tO' pass a vent 
wire through the cope at the point where the chaplet is 
to be placed, then gradually increase the size of the rod 
until nearly the size of the chaplet, when it may ht 
pressed through the sand. By thus slowly increasing 
the size of the hole, the sand is compressed and not 
cracked or loosened, as may be done when too great a 
pressure is exerted in inserting a large rod or chaplet. 
The chaplet should be drawn out when first inserted and 
the hole reamed as shown at o. This avoids the danger 
of the chaplet pulling down the sand around it, as at g, 
when the chaplet is brought to a better bearing or 
wedged down after closing the cope. Where the chaplet 
bears on the slant side of a core, the head should be bent 
at the same angle as that of the core, as at i^ tO' ensure a 
firm bearing. Where the exact shape of the core is not 
important, a level place may be filed into the core, thus 
allowing the use of a chaplet having the head at right 
angles to the stem. The chaplet must not be placed as 
shown at Ji^ Fig. 6, for it is liable to slide down the slope, 



FOUNDRY PRACTICE 37 

thus tending to displace the core or to crush the sand 
around the stem of the chaplet. 

Chaplets may be properly set in the mold and ar- 
ranged so as to give the best service possible, but still be 
rendered ineffective by improper wedging. The pres- 
sure resisted by chaplets may oftentimes be very great, 
especially in large ones. The wedges must be so placed 
that the pressure may be held without any tendencv to 
move the chaplet sidewise. This cannot be done with 
one wedge, as that gives the bearing of the stem onto 
the slant surface. The double wedge, as at ///, gives a 
firm bearing on a surface at right angles to the stem of 
the chaplet. The taper of the wedges should be very 
small so as to avoid slipping when the pressure is exerted 
on them. Many times the chaplet is too short for using 
wedges alone ; then a block must be inserted. This is as 
good as the wedges alone when the surfaces of the block 
and the wedges are kept at right angles to the chaplet. 
Some of the incorrect methods of wedging with a block 
are shown at ;z, r, and s. At //, the single wedge has been 
driven from one side, thus tilting the chaplet so it is 
liable to move over when the pressure acts against it 
The single wxdge effect is also shown at s. It is a poor 
plan to insert wedges from opposite sides of a block not 
bearing on each other, as at r and n. The block is quite 
liable to be tilted or the wedges to loosen at one side. 
causing damage. 

Another improper use of wedges is shown at t. Here 
the wedges are either of dift'erent tapers, or so placed 
that the one resting on the chaplet has a bearing only at 
the ends. This may give, or the wedge break when the 
pressure is applied. Cast iron wedges placed in this 



38 FOUNDRY PRACTICE 

manner on heavy work have been broken, thus allowing 
the core to rise. 

Wedges made of hard wood give good satisfaction in 
light work. Wrought and cast iron wedges are more re- 
liable and may be used in any case. 

The parts of a mold are held together by properly 
clamping or weighting the cope and cores before cast- 
ing. The stress upon the cope due to the molten metal 
when a flask is poured is dependent upon many con- 
ditions. The main force is that of the static fluid while 
the metal is still a liquid. A second force that in some 
cases is of great magnitude is that due to the momen- 
tum of the metal when the mold fills and the metal 
comes up in the riser. This force may be inappreciable 
in many cases. In particular cases there appears to be 
a force exerted that can not be well accounted for, but 
which must be provided against when liable to appear. 

The static, or fluid, pressure on a cope may be cal- 
culated directly. Before giving the method of determin- 
ing the force, let us understand what causes this force. 
The metal when molten is a fluid the same as water, and 
it passes from the fluid state to the solid when the tem- 
perature lowers below its fusion point, the same as water 
becomes ice as soon as it cools below 32° F. or 0° C. The 
same laws hold true with each fluid while in the same 
state of fluidity. Since water is better known, let us con- 
sider that we are handling water ; then by the change of 
weight we will have the conditions existing in the case 
of molten iron. Any body lighter than water will sink 
into its surface until it has displaced an amount equal to 
its own weight. In order to press the bodv further into 
the water a force must be exerted equal to the weight of 
the water displaced. When once the body becomes im- 



FOUNDRY PRACTICE 39 

mersed, only a slight increase of the force will sink it to 
any depth. This additional pressure is small enough so 
it may be neglected in cases that we consider. This 
gives the action that takes place upon a core that is sur- 
rounded by metal. The pressure exerted upon any sur- 
face by the water is due to the area of the surface and 
the height of the water aboye that surface. In fluids the 
pressure at any point is equal in all directions and is 
transmitted without loss throughout its entire body. Thus 
if a tank be tight and haye a small pipe extending direct- 
ly aboye it, and it be filled with water until the pipe is 
partly filled, the pressure on any cross-section is the same 
as though the tank extended at its maximum size and 
were filled to the same leyel as that in the pipe„ 

The amount of force necessary to hold down a core 
that is surrounded with iron may be found, since it will 
equal the difiference between its weight and that of an 
equal yolume of iron. Sand weigh 5 about .06 lbs. per 
cu. in., and iron weighs .26 lbs. The difference between 
the two is therefore .2 lbs. per cu. in. By finding the 
yolume of the core in cubic inches and multiplying .2 
lbs. by this number we haye the weight necessary to hold 
the core down when the mold is poured. If the core 
has metal partly around it, the pressure will be the same 
as that exerted on the sides of the mold at that leyel. 

The pressure exerted on the cope will be that due to 
the head aboye the surface of the cope and acting on 
the area of mold which the cope covers. This can be 
more plainly understood by taking a particular case, as 
a plate whose top is 12 in. by 24 in., and haying a cope 
16 in. by 24 in. and 6 in. deep. The head on the face of 
the cope will then be .6 in. The area of the mold is I2x 
24, or 288 sq. in. The yolume of metal which would be 



40 FOUNDRY PRACTICE 

equivalent to the pressure is 288x6, or 1,728 cu. in. Its 
weig-ht will be i,728x.26, or 499.28 lbs. The weight of 
the cope will be its volume in cu. in. x .06, the weight 
of a cu. in. of sand, gr 26xi6x6x.o6 — 113.76 lbs. There- 
fore the additional weight required upon the cope will 
be 449.28—113.76 = 335.52 lbs. 

The magnitude of the force due tO' momentum can 
not be calculated and is dependent upon the style of gate 
and rapidity of pouring. If the mold is poured slowly, 
the metal rises slowly and comes up in the riser easily, 
exerting no force of momentuni. If, on the other hand, 
the metal is poured in rapidly, and the mold fills quickly, 
the moment of the flowing metal lias to be overcome bv 
the cope, which stops its flow suddenly. 

The style of gate has a great influence upon the 
amount of the pressure due to momentum. If the metal 
is poured into a basin, the fall of the metal from the ladle 
is broken and the iron enters the gate with but little 
force. Therefore the pressure in the mold will be prac- 
tically that due to a head the height of the surface of the 
metal in the basin. When the metal is poured directly 
into the gate, a much greater momentum is attained 
The metal falling from the ladle into the gate attains a 
velocity and consequent energy which is exerted upon 
the metal in the gate. This gives a pressure almost equiv- 
alent to that produced by a head the height from which 
the metal falls. The allowance necessary to cover this 
extra force makes the safe weight one-half larger than 
that calculated for the statical head. This will take care 
of all otlier force not accounted for. 

Castings are often lost by putting too great a weight 
upon the cope or by drawing' the clamps too tight, thn^ 
causing a crush in the mold. 



FOUNDRY PRACTICE 41 

In clamping a cope, the main idea is to hold the flask 
firmly together so it can not strain at any point allowing 
the metal tO' run out. It is not necessary to put great 
pressure on the cope with the clamps in order to 
hold the metal. After the clamp is tight so it can not 
give, any additional pressure on the clamp is more detri- 
mental than beneficial. The clamp ehould be stood near- 
ly straight and tightened onto the wedge with a clamp- 
ing iron, as shown in Fig. 21. Clamps should be placed 
near enough together to avoid straining the flask between 
them. 

The strength of a clamp throughout its central part 
where the stress is tense may be calculated, allowing 5'~ 
000 lbs. per sq. in. of cross-section for cast iron and 15,- 
000 lbs per sq. in. for wrought iron. The greatest stress 
on the clamp is at the corner and that is dependent upon 
the leverage to the bearing point. The corner must be 
greatly reinforced to make it equal to the other part. 
Wrought iron clamps are usually made by bending a bar, 
which makes them weaker. The force they will resist is 
that necessary to bend the corner. 

The volume of a given weight of iron changes as it 
passes from the liquid to the solid state. This diminution 
of volume upon solidification is called shrinkage. The 
amount of shrinkage varies with the chemical composi- 
tion of the iron. The average shrinkage is an eighth inch 
tO' one foot in length. This shrinkage is allowed for in 
the patterns by use of the pattern scale whose dimensions 
are that amount in excess of the standard scales. The 
volume also' reduces after solidification as the tempera- 
ture reduces tO' that of the atmosphere. This is often 
treated as the contraction of the iron, but it is more sim- 
ple to combine the two^ and treat it as shrinkage. The 



42 FOUNDRY PRACTICE 

feeding of large casting is for the purpose of supplying 
metal to the interior of the casting to replace that drawn 
away by the shrinkage after the outer shell has become 
set. 

Many castings are lost due to holes in the casting 
where it should be solid and filled to the form oi the pat- 
tern. These holes may be from either or both of two 
causes : first, the casting may blow% or, second, the shrink- 
age draws away the metal from a particular point. The 
defects are called blow-holes in the first case and shrink- 
holes in the second. The causes of the first, or blow- 
holes, may be various. It is the gases failing to escape 
from the face of the mold or some core and forcing their 
way through the molten metal, leaving the opening when 
the metal sets. A few causes may be mentioned which 
are most common : too wet sand, too hard ramming, im- 
proper venting of sand or cores, wood or rusty iron 
coming in contact with the molten metal, or faces such 
that the metal will not lie cjuietly against them. These 
holes are characterized by rough, irregular surfaces, and 
have the appearance of gas enclosed. 

Shrink-holes are caused by the drawing away of the 
metal to replace the shrinkage while solidifying. These 
are caused by failure tO' supply feeding iron to the heavy 
parts after the surface has set. It ma,y be due to the form 
of the casting or to insufficient feeding when such is 
provided. The point where such a shrink-hole is most 
liable to be is where there is a break in the regular sur- 
face of the casting; as under a feeding head which was 
of insufficient size, where the gate, or riser, is cut into 
the casting, where a lighter part of the casting joins to 
the heavier part, or at the top surface when no weak 
point is adjacent. 



FOUNDRY PRACTICE 43 

These holes are characterized by smooth holes de- 
pressed into the casting with solid bases, or depressions 
in the casting having the appearance of a shell solidify- 
in o- in contact with the face of the mold, then drawn 
down by the shrinkage. When the shrink-hole is not at 
the surface it may take a very different appearance. The 
honeycombing at the centre of large castings is due to 
the shrinkage drawing the metal away from the centre 
after the outer shell has become of such strength as 
to resist the shrinkage strains. 

The remedies for such shrink-holes are to make feeding 
heads of ample size and feed the casting until the shrink- 
age is provided for, to have the feeder connected to the 
heaviest part of the casting, to supply a feeder where the 
shrink-holes appear, or, when feeding with a rod, to keep 
the feeder open until the casting is set by supplying hot 
iron in the feeding head. 

Burning on, or casting on, is the uniting of two parts 
of a casting or the forming of a new part onto a cast- 
ing. It is the welding of the cast iron parts. In order 
to form such a weld the face of the casting must be heat- 
ed to a plastic or molten state. This is accomplished bv 
pouring hot molten metal over the surface where the weld 
is to be made, until it starts to melt or becomes plastic. 

Often the arms of pulley castings break in cooling. 
When the other parts are sound, the arms may be burned 
together, forming a perfect casting. This is done by 
chipping away the edges of the break so as to expose the 
surfaces of the casting. The pullev is laid onto a sand 
bed so the top of the arm is level. A dry sand core is 
fitted about the arm at the bottom and sides of the break, 
leaving its top entirely exposed. A runner is made to 
lead the overflow away to pig beds. The burning is ac- 



44 



FOUNDRY PRACTICE 



complished by pouring a constant 'Stream of metal onto 
the break until the surfaces become plastic or molten. 
The pouring is stopped, leaving the opening between the 
cores filled, which unites the broken surfaces 

The excess of metal is chipped off, giving the re~ 
paired casting. The progress of the burning can be de- 
termined by scraping the face with a rod while the metal 
is being poured onto it. When the face of the casting 
begins to melt it can be felt to soften under the rod. 
When the hard spots are felt, the inflowing metal should 
be directed onto them until the eiitire surface softens, 
which marks the completion of the process. 

The method of casting a piece onto a casting may be 
illustrated by forming a portion of the bracket onto the 
column shown in Fig. 55. Consider the bracket to be 
broken off along the dotted line ab. The column is laid 
on the sand so the face a is level. Dry sand cores are 
fitted to enclose the bracket, giving the desired form, 
with the top side a open. A smaU hole is left through 
the core at b. A runner is led from this hole to the pig 
bed. The iron is poured onto the broken surface at the 
rate the opening will allow it to escape. The stream is 
directed onto different points until the entire surface be- 
comes plastic. The opening at b is then closed with a 
clay ball and the bracket filled with metal, which forms 
the desired casting. 

Bench molding includes the light work where the 
mold is made upon a bench and, after completion, the 
mold is placed upon the floor for casting. The bench is 
so fitted that the sandpile is under it while shelves are 
attached for holding the tools within convenient reach. 
The bench is moved back over the sand-pile as it is used, 
while the molds are placed in front in a convenient ar- 



FOUNDRY PRACTICE 45 

rangement for pouring. The molder, being in a stand- 
ing position, is more comfortable and can produce more 
molds than on the tioor in a stooping position. 

The snap-flask is especially suited to this class of 
work. Individual flasks of small sizes are also used on 
the bench. The flasks are of such sizes that they mav 
be handled easily from the bench to floor after the mold 
is finished. Ordinarily the individual flask should not 
exceed i6 in. square. 

Bench molding is used extensively in brass foundries 
The sand is mixed and tempered in a box or trough with- 
in convenient reach of the bench. 

yiost patterns have the lines of parting at different 
levels at dift'erent parts of the pattern. In these cases, 
if the pattern were laid on a plain board, the molder 
would be obliged to cut away the sand to the line of 
parting of pattern and slick the surface for the parting of 
the mold. To avoid this loss of time, a special follow- 
board is made which conforms to the pattern and forms 
the desired parting surface on the drag. 

A match is a follow-board made from new^ sand 
rammed hard, core mixtures, or any convenient material 
that will maintain its shape firmly. A match is often 
made for the present use for a special order. With 
standard patterns the match is made permanent and goes 
with the pattern. A permanent match may be cheaply 
made of core mixtures. The preferable mixture is that 
of linseed oil and fine sand, because it holds its shape 
firmly and is not affected by damptiess. 

When there are not enough castings to be made from 
a pattern to pay to shape a special follow-board, and the 
pattern projects into the cope, it is often desirable to 
make a match of green sand in the cope with the pattern 



46 



FOUNDRY PRACTICE 







FOUNDRY PRACTICE 



47 



at its proper location. The drag is rammed up in its 
position on the cope. When turned over the cope is re- 
moved, the sand is cleared away, and the parting of the 
drag is prepared for ramming the cope. 

A plain board is used as a turn-over or foUow^-board 
with patterns having- plain surfaces or the parting nearlv 
in the plane of the face of the drag. 

Molding machines are for the purpose of expediting 




Fig. 8. 

the operation of molding. The term molding machine 
does not mean that the machine will do the work of 
forming a mold. The molding machines may be classi- 
fied under three general heads : first, the machine for 
mechanically drawing the pattern ; second, the moldinp 
press; and, third, the machine with press and mechanical 
drawing of the pattern. 



48 



FOUNDRY PRACTICE 




FOUNDRY PRACTICE 



49 



In the first class of machine, the sand is rammed 
by hand in the usual manner. When ready to be re- 
moved from the machine, the pattern is drawn down 
bv mechanical means, usually a lever or rack and pinion. 




Fig. 10. 



The pattern is drawn through a stripping plate which 
prevents the sand from tearing and makes possible the 
performing of the operation more rapidly. The hand is 



50 



FOUNDRY PRACTICE 



unsteady and can not hold the pattern so as to move it 
out of the mold perpendicular to its face ; hence, it takes 
much time and skill to draw the pattern without tearing 
the mold. 




This type of machine is suited to a wide range of 
castings. Many manufacturers of molding machines are 
fitted to huild a machine for a very great variety of pat- 
terns. One machine of this class is shown in Fig. 7. It 



FOUNDRY PRACTICE 51 

is for making" pulleys of any desired size and width of 
face up to about 44 in. diameter with 24 in. face. The 
range for each machine is about 12 in. on the diameter; 
i. e., a machine will make all sizes from 6 in. tO' 18 in. 
in diameter. The changeable parts are the pattern ring, 
the arms, and the stripping plates for each size as 
shown in Fig. 7. The cope and drag are rammed on the 
same machine, and the pins are so arranged that the 
joint comes together correctly when the flask is closed. 

The machine shown in Fig. 8 is one of a great variety 
of machines which are for a special casting. One ma- 
chine forms the cope while the other forms the drag. 
These two machines are combined in one for some pat- 
terns ; then each flask contains two castings. Special 
flasks are required for all this type of machine. 

The second class of machine performs the operation 
of ramming the sand in the flask, while all the other op- 
erations are performed by hand. Fig. 9. represents a 
press molding machine, or "squeezer." The machine ful~ 
fills the offices of the bench used in bench molding, and 
also has the presser head which compresses the sand into 
the flask instead of ramming by hand. The work hand- 
led on these machines is the same as that done on the 
bench. The snap flask is used on all small machines. 

Fig. 10 represents a press molding machine having 
pneumatic connections. The pattern is loosened by the 
vibrator frame when the cope is readv to be lifted. 

Fig. II shows a multiple mold made l:)y the use of a 
press molding machine and the casting that is obtained 
from the mold. This secures the making of a great num- 
ber of molds on a small floor space. 

The third class of molding machine performs the op- 
eration of ramming and drawing the pattern. Fig. 12 
shows such a machine for making ells as shown at the 



52 



FOUNDRY PRACTICE 



bottom of the figure. The presser head conforms to the 
pattern leaving the cope as shown after the sand has 
been compressed. Before compressing the sand into the 
flask, the sand frame is placed upon the flask and filled to 
its top. The degree of hardness due to the press is de- 
pendent upon the depth of this sand frame. After strik- 
ing off and venting, the flask is lifted off from the pat- 




Fig. 12. 

tern by the lift lever, thus mechanically drawing the pat- 
tern. The pattern board forms the stripping plate. 

These machines are made for many special patterns 
and are claimed to give good results; and they very 
much reduce the cost of making the mold. 



I 



CHAPTER II 

The method of proceeding in n.aking a mold for a 
plain casting may be demonstrated by consideration of 
the pattern shown in Fig. 13. After having the sand 
properly tempered, the turn-over board is placed on a 




£ 



Fig. 13. 



sand bed so as to have bearing all over to avoid rocking 
or unevenness of the top. The pattern is then placed 
on the board as shown in Fig. 14. The drag may now 



54 



FOUNDRY PRACTICE 



be placed over the pattern and facing sand riddled onto 
the pattern. After the pattern is covered with a light 
coat of facing sand, heap sand is riddled to about the 
depth of 6 in. as shown in Fig. 15. The sand is 
rammed around the edge of the flask with the pein ram- 



Fig. 14. 

mer by directing it as shown at A, Fig. 15. It is next 
rammed around the pattern with the rammer directed as 
shown at B, Fig. 15. The sand falling between these 
twO" rammings is then rammed to- an even hardness which 



1 



A 



B 







¥iii. 1;. 



is sufficient to form a firm body and allow the free escape 
of the gases. 

Care should be taken in ramming, to avoid striking 
the rammer nearer to the pattern than one inch. Wher- 



FOUNDRY PRACTICE 



55 



r^^ 



^rc^mmi CO ^ 




Fi^^ i6. 

ever the pein strikes the pattern, a hard spot in the sand 
is left which will cause a scab on the casting. The flask- 
is now filled full of heap sand and rammed with the butt 

177 




Fig. 17. 



56 



FOUNDRY PRACTICE 



rammer as shown in Fig. i6. The drag may now be 
struck off with a straight edge even with its top. A thin 
layer of loose sand is then scattered over the sur- 
face to ensure a good bearing on the entire surface of 
the bottom board. The drag should now be vented with 
one-eighth in. wire all around and over the pattern using 




Fig. i8. 



care not to strike the pattern so as to allow the metal to 
flow into the vent. The bottom board is placed onto the 
drag, with care that it touches at all points. The two 
boards are clamped to the drag with short clamps as 
shown in Fig. 17. The flask is then turned over onto a 
bed of loose sand, so as to have an even bearing at both 



FOUNDRY PRACTICE 



57 



ends. The clamps are then removed and the board taken 
off, leaving the pattern at the top of the drag. The joint 
is made by tucking sand into any soft places that there 
may be, then the surface is slicked with the trowel by 
leaving a little loose sand on the surface so as to make it 
a little harder than the other parts of the sand. Parting 
sand is dusted over the sand of the joint until the entire 




'• '• ;•• -*' '}-: \': 'i:'V^ *i^A' v / ; •/.'•'. ':".•'• ''.';• 

. ..^ - ••;.• • • .• . •'.. '• '• " ; '. .. « !' 



X ,' . *.^ 






;- »;..% >. 





Fig. 19. 

surface is covered. That falling onto the pattern is 
brushed off. Since the flask is small and the cope has no 
bars, it may now be placed on and the gate stick set even 
with the centre of the pattern and midway between the 
flask and pattern as shown in Fig. 18. This pattern hav- 
ing a rib running lengthwise, the inflowing metal should 
enter the rib from an end and not over an edge. This 



58 FOUNDRY PRACTICE 

will reduce the liability of the metal cutting away the 
sand causing a bunch on the casting. A little facing 
sand is riddled over the pattern, then the heap sand is 
riddled through a No. 4 riddle to :i depth of about one 
inch. Heap sand is filled in and rammed next to the flask 
with the pein, then the remainder is rammed to an even 
hardness. The cope is filled and rammed with the butt 
rammer and struck off similarly to the drag. It is vented 
over the pattern and around the gate stick with one- 
eighth inch vent wire. The gate stick is loosened by rap- 
ping sidewise, then it is withdrawn. The hole is reamed 
out, leaving a large opening to pour the iron into, as 
shown in Fig. 19. The cope is ready to be lifted ofif and 
placed on any convenient rest where it may be finished. 
The cope should always be finished before the drag is 
touched, for, if anything happened to necessitate shaking 
it out, the drag is ready to have the cope replaced for an- 
other ramming. The portion of the cope that covers the 
pattern should be slicked lightly with the trowel, then 
covered with plumbago with a soft camel's hair brush, or 
by dusting from a sack and then slicking with a trowel. 
The gate should be reamed slightly to take off the loose 
edge and pressed to firmness with the fingers. The drag 
should be brushed ofif to remove the parting sand ; then 
wet the sand around the pattern slightly with the swab. 
If the sand is too wet at any point the metal will blow 
when poured, therefore care must be exercised in putting 
on only as much water as is necessary to make the sand 
stick together well. The pattern may now be drawn by 
driving the draw spike into the centre of the pattern, 
then rapping it until the sand is free from the edges of 
the pattern; then lift the pattern out by slowly raising 
it as shown in Fig. 20. The mold is slicked over lightly 



FOUNDRY PRACTICE 



/\ 



59 



. • • * ■ ■ 



:-fc>- ••.^- •■••■;' ^'^v: 



V 




6o 



FOUNDRY PRACTICE 



and patched in case the pattern tears the sand at any 
place. The pouring gate is now connected to the mold 
by cutting a runner from the mold to the gate of a size 




Fig. 21, 



that will admit the iron freely, but it must be smaller 
than the portion of the casting where it connects so that 
the runner may be broken off easily without damage to 



FOUNDRY PRACTICE 



61 



the casting. The runner should be smoothed with the 
fingers or a shaking tool to ensure against loose sand 
being washed into the mold. The mold may now be 
dusted with plumbago and slicked, at which time the 
flask is ready to close. The flask should be clamped 
to provide against the cope being lifted by the metal 
and the metal flowing out at the joint when the 
mold is poured. In clamping a flask, it must not be 
moved or jarred, as the sand hanging at the top is 
liable to drop. Nor should the cope and drag be drawn 
together with a great pressure as the flask is liable to 




^ 


\ 



Fi^^ 22. 



give, causing the sand to crush in the mold at the joint. 
The best method of putting on the clamps is to have 
them stand nearly vertical an^ resting on a wedge at 
the top. The clamp may be tightened with a clamping 
iron by catching the point under the clamp and on the 
wedge, then moving the upper end toward the clamp as 
indicated by the arrow in Fig. 21. The mold is now 
ready to cast. 

The process of making a mold with a split, or divid- 
ed pattern is shown by the small pulley in Fig. 22. The 
half of the pattern without the dowel-pins is placed on 



62 



FOUNDRY PRACTICE 



the turn-over board and the drag- placed on it as in the 
previous case. The facing sand is nut on until the arms 
are covered, then heap sand is riddled through a No. 4 
riddle until the centre is filled to the top of the rim. 




Fig. 23. 

Since the hub is deeper than the rim, there is liability of 
the sand crushing out when the mold is poured, as the 
hub fills to the height of the arms before the rim receives 
any iron. To prevent the sand from breaking and to 
hold it together more firmly, wooden soldiers are put 




Fig. 24. 

into the sand between the rim and the hub. The soldiers 
are made of any small pieces of wood, only large enough 
to be stiff and of a length to reach beyond the pattern 
about the same distance as it is inserted into it. They 
are wet with clay wash, or tlour paste, to hold the sand to 



FOUNDRY PRACTICE 



63 



the soldier. They are placed to a depth of the arms about 
midway between the rim and hub, and between the arms, 
as shown in Fig. 2^^. 

The pattern is now completely covered with riddled 
sand and the outside rammed as before. The sand with- 
in the pattern is rammed with any small tool or stick that 
can be gotten in between the soldiers and the pattern. 
The remainder of the drag is filled in, rammed and 
vented. The fiask may now be turned over and the joint 
slicked as before. The other half of the pattern is put 
on as shown in Fig. 24. Parting sand is put over the 



N^:. •:.•...•.•;■;.; •...;-;•' 




1.!.- . * .-' A 



^^^^^^^^^^$^^:<^>$^^^ 




Fig. 25. 

joint, then the cope is placed in position. Pulleys and 
wheels should always be poured from the hub, so the 
gate stick must be placed above the hub. The facing- 
sand is put on the arms and hub, and riddled sand filled 
in over the pattern. Soldiers may now be placed in the 
same manner as in the drag, but their office in this place 
is more to hold the sand from falling away when the 
cope is lifted ofT or closed after removing the pittern. 



64 



FOUNDRY PRACTICE 




be 



FOUNDRY PRACTICE 



65 



The first ramming is the same as the drag, then the gate 
stick may be put in place and the ramming finished. The 
cope is vented, the pouring basin cut and the gate stick 
removed giving the flask in form as shown in Fig. 25. 
The cope is Hfted ofif and placed on any convenient block- 
ing, as shown in Fig. 26. The pattern in the cope is 
brushed off and lightly swabbed with water. 

The pattern is rapped and removed, by lightly jarring 
as it is drawn. The gate is reamed a little at the hub to 
remove loose sand, then the hub and arms are slicked 
and blackened with plumbago. The drag is prepared m 
the same manner, then the fiask is ready to close and 
clamp for casting. 





Fig. 27 



Many patterns have rounded edges or have the point 
of parting located at different levels in various parts of 
the pattern. In these cases the parting on th,e drag must 
be shaped to allow the pattern to be withdrawn without 
destroying the shape or tearing up the sand. The upper 
portion of the pattern must be formed in the cope. This 
causes a portion of the sand to be hung in the cope below 
the level of the flask, or the sand is coped out to the pat- 
tern. In cases of coping out, a portion of the sand is 
lifted from the pattern when the cope is lifted ofT. This 
does not admit of rapping the pattern or otherwise loos- 
ening the sand, therefore the sand must be well anchored 



66 



FOUNDRY PRACTICE 



so as to hold its form well and not require too much 
patching. 

The pattern of the half of an eccentric strap, shown 
m Fig. 2"], may be taken as an example where coping 
out is necessary. The pattern can not be drawn side- 
wise, as the inner circle has a flange on each side. 





Fig. 28. 



To cast this eccentric strap, the pattern is placed in 
the drag with the inner circle toward the turn-over 
board, then facing is put on the pattern and the drag 
filled, rammed, vented, and turned over as in previous 
cases. The parting is now made even with the face of 
the drag at each end up to the edge of the inner circle. 



FOUNDRY PRACTICE 67 

The part then follows the outer edge of the pattern and 
the sand is sloped outward on each side, as shown in 
Fig. 28. This slope must be so as to allow the sand to 
part freely at all points when the cope is lifted. The 
dry parting sand is then placed over the level portion ot 
the drag, but it will not stay on the slope. A good part- 
ing sand for that part is fine new sharp sand dampened 
and spread in a thin coating over the slope by slicking on 
with a trowel or the hand ; over this dust the dry parting 
sand. 

The cope -for a pattern like this must have special 
bars following near to the shape of the pattern, as shown 
in Fig. 29. The bars must be dampened with clay wash 
or thin flour paste to make the sand stick to the bars. 

Facing is riddled onto the pattern and sand riddled 
over the drag to a depth of about one-half inch. The 
flask joint is then cleared and the cope is put in place. 
The gate stick is placed opposite the centre of one end, 
while a riser is placed at the other. The offices of the 
riser are to allow the gases to escape from the mold and 
to furnish iron to feed the casting when shrinkage takes 
place. 

Gaggers are then set in the cope, observing the pre- 
cautions previously given, and are placed near enough 
together to anchor the sand firmly in the cope. The 
sharp edge coming inside of the flanges may be better 
anchored by placing nails with heads toward the 
pattern at intervals of about one to two inches. The 
nail heads should be clay-washed and set as soldiers. 
Sand is now riddled into the cope to a depth of two or 
three inches, then the bars are tucked with the fingers to 
harden the sand under the bars, the same as the rammed 
portion between the bars. Sand is filled in to a depth of 




Fig. 2q. 



FOUNDRY PRACTICE 69 

about 6 in. The part enclosed between each set of 
bars is rammed separately, similarly to an individual cope, 
but using care to have all the divisions rammed to an 
even hardness. The remainder of the cope is then filled 
in and rammed, having about 6 to 8 in. of sand 
to a ramming, until the cope is entirely filled, when it is 
butted ofif and vented. In ramming, the operator must 
avoid striking the gaggers, as that drives them into- the 
drag and then necessitates patching when the cope is 
lifted ofT. The cope may now be lifted ofT, using care 
to lift it slowly and evenly in order that the sand may 
not be torn by striking at any point. The cope should be 
gone over with the hand to see if there are any soft spots, 
which when found should be filled to an even hardness 
with other parts. It is then patched where necessary and 
slicked to a smooth surface. The pattern is drawn from 
the drag after removing all the parting sand and swab- 
bing the sand at the edge of the pattern. The mold is 
slicked and the gate and riser connected to the mold by 
the runner. This gives the mold in the form as shown 
in Fig. 30. The mold may be blackened and closed, 
ready tO' be cast. 

Many patterns are of such form that they require a 
special follow board or match in order to mold them by 
turning over. When there are not enough castings re- 
quired tO' pay to make a follow-board, other means must 
be resorted to. If these are of such form that they may 
be evenly rammed by bedding in, that method often 
saves much time. 

To mold by bedding in is to place the drag in the po- 
sition it is to have when the cope is put on, then 
ram the sand in until it is of such a height as to bring 
the parting of the pattern at the parting of the flask, and 



70 



FOUNDRY PRACTICE 




to 



FOUNDRY PRACTICE 



71 



finish the ramming of the drag with the pattern in posi- 
tion. Many forms of patterns easily admit of this method, 
in that there are no parts that are not easily accessible 
for ramming the sand from the top side. Other patterns 
may be such that a molder may easily patch any soft 
spots that are under the pattern when finishing the mold. 
In some places the main portion of the molding is 
done by this method, but on the majority of patterns it is 
easier and quicker to prepare the drag by turning over. 
In England where iron flasks are used, the main method 




? 



Fig. 31. 

used is that of bedding in, due to the weight and to dif- 
ficulty in turning over the flask. 

The molder must use his discretion in deciding which 
method he should use in order to save time and labor. 
Different men making the same pattern may be able to 
do the best and quickest work by using opposite methods, 
according as each is most accustomed. 

One type of castings that may best be made by bed- 



^2. FOUNDRY PRACTICE 

ding in may be illustrated by the making of a large plain 
plate by use of the frame shown in Fig. 31. The pat- 
tern is made in frame so as to be able easily to ram the 
sand that comes under it. The narrow frame may easily 
be tucked to the required hardness, while if a solid pat- 
tern be used an even hardness is much more difficult to 
obtain. 

In making the m.old, the drag is placed on the bottom 
board in the position to receive the cope. Sand is shov- 
elled in and rammed to a depth that will hold the top of 
the pattern nearly to a level of the parting of the flask. 
Sand is then riddled into the drag to a sufficient depth 
for putting the pattern in place and tucking the sand 
firmly under it. The pattern is placed in position and 
forced to the level of the drag, then it may be held bv 
placing a weight on it to avoid raising while tucking sand 
under it at the soft places. The remainder of the drag 
is rammed to the parting. The drag is well vented be- 
fore making the parting, to close the top of the vents, 
thus forcing the gases out at the bottom board. The 
cope is placed on, rammed, and lifted bv observing the 
precautions previously given. 

In order to make a plate of the mold, the sand within 
the frame must be taken out to a depth equal to that of 
the pattern. In order to make tliis of even depth, a 
strike stick as shown at A, Fig. 31, is used to strike out 
the sand. The pattern is then removed and the surface 
is slicked to an evenness, using care not to cause hard 
spots. The mold may now be blackened and runners cut, 
when it is ready to close. 

When a mold is made in the sand on the floor without 
a cope to cover it, it is called open sand molding. This 
is a cheap form of molding for some types of castings 



FOUNDRY PRACTICE 



7Z 



The casting will not be clean or smooth but may have its 
exact form all except the upper surface. 

This method may be used for making castings for 
parts of iron flasks, clamps, core irons, floor plates, or 
castings whose upper sides may be rough and where the 
exact thickness of metal is not important. 

Many of the precautions necessary to obtain a good 
casting from open sand work may be noted in the pro- 
cedure for making the flask bar shown in Fig. 32. The 
manner of makino- molds of this style varies, as is mos: 




t] 



Fig. 32. 



convenient with the material the molder has at hand. 
The method given below is most flexible and may be 
used on a great variety of patterns. Particular cases may 
be handled in very different manner. 

The top surface of the pattern must be level in aP 
directions, for the metal when poured is a liquid which 
seeks' its level. The metal lies on tlie sand with only the 
thickness of the casting. Since there is no head, as in 
gates and risers, to give a pressure, the sand must be 
open and well vented to give a free escape to the gases. 



74 FOUNDRY PRACTICE 

or they will force through the iron and cause the sand 
to cut away, making- a bunch on the casting or leaving 
blow-holes through the iron. 

The pattern here shown has the lower face a plane ex- 
cept for the flanges at each end. We may therefore 
make a level bed and place the pattern onto it. To^ make 
the bed, two straight pieces, preferably T rails, are 
placed on the floor and leveled. One piece is placed 
down and leveled with a spirit level, then the other is 
laid parallel with it at a distance that will give ample 
room to locate the pattern, with the pouring basin coming 
at the edge of the bed. This piece is made level with 
the first by use of a straight edge resting on each piece 
and the level on the upper parallel edge of the straight 
edge. Sand is filled in almost to the top of the pieces and 
rammed lightly to an even hardness. The remainder is 
filled with riddled sand and rammed lightly. Unless the 
sand is very open, the bed should be well vented down- 
ward with cross vents, allowing the gas to escape to tht 
sides. The bed is then struck off with a straight edge 
resting on the leveled pieces, thus giving an even and 
level bed. 

The pattern is then placed on the bed in the position 
most convenient for pouring. It may be driven down 
part the depth of the flange, then drawn out and the de- 
pression of the flanges cut with a trowel to soften the 
sand, to avoid its becoming too hard when the pattern is 
forced down to the bed. The pattern is replaced and 
forced down to a bearing on the bed. The edges may 
then be tucked a little to harden the sand on which the 
edges rest. Sand is filled in and tucked with the hands 
around the pattern until the sand is above the top of the 
pattern. The top is struck off even with the pattern by 



FOUNDRY PRACTICE 



75 



any short straight edge, and the surface shcked with a 
trowel. The pouring basin may be built at the end by 
making a U-shaped mound of sand with the enclosed por- 
tion tapering down away from the edge of the pattern. 
The object of this depression is to hold some metal on 
which the inflowing metal strikes instead of on the sand. 
The pattern may be removed from the mold after 
swabbing the edge and rapping to free the sand. The 
bottom is slicked smooth with the trowel, care being used 






Fig. 33. 

not to make hard spots. The flange may be patched to 
proper shape whenever necessary, then the mold is ready 
to receive the metal. 

In the case of coring holes through the plate, the 
prints may be on the lower side of the pattern when 
placed on the bed. The cores near to the entering metal 
should be supported by nails to avoid washing out bv 



76 



FOUNDRY PRACTICE 




J 



3 
3 



Ph 



FOUNDRY PRACTICE ^J 

the flow of the metal. It is a good plan to put a few 
nails at the edge next to the basin to avoid its breaking 
in when poured. 

Many castings require dry sand cores for making 
holes and openings in the castings that are solid in the 
pattern. In these cases the pattern has a print which lo- 
cates the core and holds it in position in the mold. The 
core must be A-ented off in the mold to allow the gases to 
escape freely. It must be properly anchored by bearing 
on the sand or by chaplets to prevent its floating when 
the iron surrounds it in pouring. 

Some of the principles involved in setting cores are 
illustrated in making the casting shown in Fig. 33. This 
is the casting for a headstock whose bodv part is hollow 
and having the bearings cored for babbit. 

The pattern used is shown in Fig. 34. This is a one- 
part pattern having loose pieces for the projecting parts. 
In this case the loose pieces are held in place by a dove- 
tail. Usually loose pieces are pinned onto the pattern. 
In cases where loose pieces are pinned on, the sand \% 
rammed around the loose piece, then the pin is drawn, 
leaving it free from the pattern when it is withdrawn 
from the mold. 

The drag and cope are rammed in the usual manner 
of a common mold. When the pattern is drawn from the 
drag, the loose pieces remain in position in the sand ; as 
at T, Fig. 35. The mold should be patched and finished 
before drawing the loose pieces. The edge of the large 
pieces should be nailed with short nails to prevent tearing 
or dropping when the piece is removed. The nails should 
be slanted away from the pattern and pressed in so the 
head comes even with the surface. The loose piece is 
then loosened from the sand by rapping, and drawn into 



78 



FOUNDRY PRACTICE 







FOUNDRY PRACTICE 79 

the mold, as at B, Fig. 35. These new parts are then 
finished and the mold may be blackened all over. 

The cores are placed into the inold after the manner 
shown in Fig. 36. The cores are vented off at the bot- 
tom by running a vent wire down from the print, then 
inserting another wire on the bottom board to strike 
the former. Several vents must be made in this manner 
to ensure free escape of the gases. This being a com- 
pound core, those at the bottom must be set first. The 
small bearing cores go into the opening left by the print 
on the loose pieces A and B, Fig. 35. The main core has 
a bearing on each of these cores and is held in place bv 
the side of the mold which was formed by the main print 
of the pattern. 

The upper vents of the core should be closed with 
sand or flour tO' prevent the metal flowing into the vent 
if it should get above the core. The print in the cope 
holds the upper side of the core in position, thus pre- 
venting the liability of moving side wise when the mold 
is cast. The mold may be closed w1ien the gates and run- 
ners are properly cut. 

Many patterns are of such form that thev can not be 
drawn from a two-part flask, in which case an intermed- 
iate portion called a cheek is required. This branch of 
molding is generally known as three-part work. The 
flask used and the methods of procedure are dependent 
upon the pattern. These are greatly varied. 

To illustrate one of the general forms using a 'plain 
cheek," we have taken for an example the piston spider 
for a Corliss engine, shown in Fig. ^^. The pattern, as 
shown in Fig. 38, is in two parts. The main or bodv con- 
sists of the outside ring as shown in the figure. The 
other portion consists of the centre hub with web con- 



8o 



FOUNDRY PRACTICE 







FOUNDRY PRACTICE 



8i 



necting it to the ring. The bosses in the pockets are 
loose and dowelled onto the body portion of the pattern. 
To ensure a firm, clean casting, it is advisable in this 
case tO' run some metal through the mold after it is filled. 
The mold is poured from the bottom, thus providing a 
skim gate and allowing the metal to rise in the mold 




Fig. 37. 

without flowing across the overhanging portion of the 
cheek. 

To form the mold, the pattern is placed on the fol- 
low-board with all the parts in place. Facing sand is put 
into the pockets to a depth of about 2 in. Long 
rods are placed in the pockets to securely anchor them 
in the cope. Fill in about 2 in. more of facing and ram 
lightly with a rod or stick, using care to avoid making 
the sand too hard. The remainder of the pocket is filled 
and rammed. The dowels may be removed from the 



82 



FOUNDRY PRACTICE 



i 




S ^F^ ^s^ 







I 



^^^^ 







X~7 




y\ 




FOUNDRY PRACTICE 83 

bosses. The pockets should now be thoroughly vented, 
using a needle wire smaller than Yj,^ in. in diameter. 

The cheek may be placed on the follow board about 
the pattern. The gate stick is placed in its position out- 
side of the pattern. The cheek is now rammed and the 
parting made at the upper edge of the ring. The cope 
may be placed upon the cheek. T'le pouring gate from 
the cheek extends through the cope, and a flow-off gate 
is placed on the centre hub beside the centre core. The 
cope is rammed, ensuring proper anchorage for the rods 
from the pockets. It should be well vented, especiallv 
above the pockets. The gate sticks are then removed. A 
bottom board is placed upon the cope, the flask firmly 
clamped together, and the whole turned over. The fol- 
low-board is removed and the lower parting made on the 
cheek. 

The core print is placed on the pattern. The drag is 
rammed, having proper anchorage for lifting it ofif. Af- 
ter venting the drag is lifted off and placed on a bot- 
tom board bedded for receiving the flask. The drag is 
slicked and finished. The surface directly in front of the 
gate is nailed to prevent the iron from cutting awav the 
sand. 

The body portion of the pattern is drawn from the 
flask. The top of the cheek is finished and the runner 
cut to connect with the pouring gale. The cheek is lift- 
ed off and completely finished and blackened, then placed 
in its position on the drag. Before removing the second 
portion of the pattern from the cope, the edges of the 
pockets should be well nailed to better anchor the sand. 
The pattern may now be drawn and the cope finished and 
blackened. After setting the centre core, the flask may 
be closed. The gate sticks are replaced in their respec- 



84 FOUNDRY PRACTICE 

tive positions, in order to form the overflow runner and 
the pouring basin which must be higher than the flow-off 
gate. To prevent closing the vents in the cope, when 
the flow-ofl!^ gate is made, the surface is covered with 
paper, hay, or any convenient material. The gate is 
made having a runner to conduct the overflow from the 
flask. After clamping it is ready to receive the metal. 

In some cases it is found that dirt accumulates in the 
flange directly above the gate where the metal enters. 
It acts as a whirl or retaining point that is not forced 
to circulate as the metal is flowing into the mold. To 
avoid this, it is advisable to put a top gate on the opposite 
side of the centre core from the flow-off gate. 

Many forms of patterns recjuiring three-part flasks 
are such that the "cheek can not be lifted." In 
such cases the lower portion of the pattern is drawn and 
that part of the mold finished before the drag and cheek 
are rolled over. 

The lathe bed casting shown in Fig. 39 gives a good 
example of this class of work. The pattern has the two 
upper rails loose with the fillets attached forming the 
guides to hold them in place. 

This casting may best be gated so as to allow the met- 
al to enter at both top and bottom rails thus reducing 
the liability of the metal cutting, from too great a flow 
at the bottom or by falling from the top of the mold. 

The cheek is placed on the follow-board and the pat- 
tern placed with the cope side down, in which case the 
loose rails come on the upper side. The gate stick is 
placed in position so that runners may be cut to the low- 
er rails. The pattern is then faced on the outside and 
rammed in the usual manner. The inner portion will 
be a green sand core which is separate from the flask and 



FOUNDRY PRACTICE 



85 



has bearing at top and bottom. In the 
centre of each should be placed a vent 
rod to give a conduct for carrying off 
the gases. The sand is filled in and 
rammed to a depth of about four inches. 
Rods are now laid in diagonally to bind 
the sand together. Use facing next to the 
pattern and riddled sand for the remain- 
der. Each succeeding ramming of from 
2 to 4 in. should be well rodded, laying 
them in different directions each time. 
When the cross webs of the pattern are 
covered, it is best to place two or three 
long rods in to bind the whole core to- 
gether. 

When the cheek is finished the parting 
is made even with the top of the pattern. 
The face of this parting should be hard- 
er than in the previous cases, because the 
pressure head of the metal is very great 
as this comes at the bottom of the mold. 
A good method of getting this parting of 
even hardness is to riddle some sand on- 
to the surface to a depth of about 2 in., 
dien butt in firmly but not hard. 

Strike it off with a stick, then slick 
with a trowel after riddling on a little 
sand over the entire surface. The gate 
stick should come to this surface but not 
extend beyond. Parting s^nd is put 
on and the drag rammed, vented and 
lifted off. 







86 FOUNDRY PRACTICE 

The cheek should be well vented on the outside of 
the pattern and under the rail that is about to be drawn. 
These vents should be led off to the parting- of the flask. 
The centre portion should have vent gutters cut around 
within about 2 in. of the pattern and leading to the centre 
vent rod of each of the cores. The vents are all made to 
extend from this gutter. The wire should be Ys or ^/i^ 
in. in diameter. Vent particularly under the rails and 
around the centre web. 

The parts of the pattern are drawn. The edges of 
the fillets near the web or the part of the pattern still 
remaining in the mold should be nailed, using 10-^. nails 
and placing them about 2 in. apart. The mold is theu 
slicked, blackened, and gates cut from the rails to the 
gate stick. The drag is then closed onto the cheek. Sand 
should be throw^n onto the top and struck off evenly. 
This may be easily accomplished by using a straight 
edge with a gagger or strip of wood under it and bearing 
on the flask. The bottom board is placed on and rubbed 
to good bearing, then the flask is clamped together firm- 
ly and turned over, using care not to strain the mold. 
The follow-board is removed and the upper parting mad(. 
on the cheek. 

The cope is then rammed, having a riser opposite the 
gate and the vent rods drawn up to give opening through 
the cope. This is lifted off and finished in the usual 
manner. The cheek is vented under the rails on the out- 
side of the pattern and the vents led off to the parting. 
In venting, do not endanger forcing the wire into the 
lower part of the mold where the pattern has been re- 
moved. In the centre portion, vent gutters should be cut 
around each core and led to the centre vent ; then vent 
the core to lead to these gutters. The pattern mav now 



FOUNDRY PRACTICE 



87 



te drawn and the mold slicked and blackened. Runners 
are cut to connect the rails to the main gate. The cope 



rA 




c 






Fig. 40. 



may be closed, the pouring basin made, and the riser 
built to the same height. 




Fig. 41. 



In this mold there is a depth of metal which causes a 
pressure against the side. This must be provided for in 



88 FOUNDRY PRACTICE 

clamping the mold. A tie clamp mny be placed over the 
flask, having the parallel ends long enough to reach to 
the bottom of the cheek. Wedges are placed between the 
clamp and the flask, and forced to a firm bearing, but 
must not spring the flask. These may be driven in hard 
enough by striking with a hammer handle. In these cas- 





Fig. 42. 



es, be very careful not to put great pressure at the sides, 
for the flask will be forced together, making the metal of 
the web too thin or making it cut through to the cheek. 
In making many castings much time may be saved 
by making "three-part work in two-part flasks." This 
may be accomplished by using a cover core over the bot- 
tom division of the mold when that is a plane surface. 



FOUNDRY PRACTICE 



89 



In other cases the cheek portion may be made in the sand 
alone. This latter form may be shown by the sheave- 
wheel made from the pattern shown in Fig. 40. There 
are two other methods of making this, and the method 
chosen depends mainly upon the size of the wheel to be 




Fig. 43- 

made. Fig. 41 represents a three-part flask with the 
cheek so it may be lifted. Fig. 42 is a two-part flask 
having the third or cheek made in core. After the pat- 
tern is drawn out, cores of the form shown at A are set 
in the place of the print on the pattern. This method is 




Fig. 44. 

of great convenience when there are two or more grooves 
in place of the single groove here represented. The pat- 
tern is made in halves as shown in Fig. 40. The process 
of molding would be to ram the cope as usual with the 
pattern in the centre of the flask as shown in Fig. 43, 
having the gate stick placed on the hub. The flask is 



90 



FOUNDRY PRACTICE 



turned over and the parting made to slope down to the 
parting hne of the pattern as shown in Fig. 44. The oth- 
er half of the pattern is put in place and weighted so as 
to ensure its remaining in place while the cheek is made. 
The cheek is made by tucking in about the pattern until 
filled so as tO' make the upper parting as shown in Fig. 
45. The drag may now be put in ])lace and rammed. It 
must be sufficiently anchored to allow lifting off. 

The drag is then lifted off and that half of the pat- 
tern drawn and the mold slicked and finished, as shown 
m Fig. 46. The drag is replaced, and the bottom board 
given a firm bearing by use of loose sand on the fliask, 




^^^^^;^^^^^^^^^^^^^^ 



Fig. 45- 

then turned over carefully onto the bed where it is to re- 
main. The cope is now lifted and the remainder of the 
pattern drawn and the mold finished. In lifting a part 
of the flask where the pattern is lifted with it, a draw 
spike, or wood screw, should be put into the pattern and 
held when the flask is lifted. The centre core is set,, 
then the mold may be closed. A pouring basin should 
be built on the runner so that the iron may strike in the 
basin instead of directly into the gate. This breaks the 
fall of the iron from the ladle and relieves the straining 
pressure on the mold, besides acting as a skim gate when 
the basin is kept full. The dirt and slag float on top, 



FOUNDRY PRACTICE 



91 




fe 



92 



FOUNDRY PRACTICE 



while the clean metal enters the mold from the bottom 
of the basin. This gives the mold as shown in Fig. 47. 

The use of cores for covering part of the mold in- 
stead of a third part to the flask is found to be of great 
advantage when making large baseplates for columns. 
Fig. 48 shows a baseplate casting which may be made by 
use of cover cores. 

The pattern for this casting has the top and bottom 
pieces dowelled to the centre piece and the ribs, while the 
ribs are also separate from one another. The pattern in 




Fig. 47. 



its complete form is placed on the foUow-board in the 
drag. The bottoms of the pockets are faced and filled 
with sand to a depth of about 3 in. This is rammed 
lightly, then long rods are laid in horizontally, extending 
out to the flask. Two rods should be placed in near the 
corner of each pocket and slanting upward to just allow 
room for the cores to be placed on the top without strik- 
ing the rods. These rods should not strike the pattern. 
The buoyancy of the nietal, acting on the bottom of the 
sand which forms the pocket, is held by these rods placed 



FOUNDRY PRACTICE 



93 




w-B 




Fig. 48. 



94 FOUNDRY PRACTICE 

in the sand. This buoyancy, or Hfting force, acts on the 
surface exposed by the lower plate proportionally to the 
area exposed and the height of the pressure head. About 
3 or 4 in. of sand is filled into the pockets and rammed 
about the rods with a small rammer, care being used to 
have the rods firmly rammed into place and not sprung 
so as to tear the mold when the pattern is drawn. This 
should be well vented in the pockets and a coke bed for 
collecting the gases laid into the pockets and leadinr^ to 
the flask where the gases may escape. The coke bed is 
covered with sand to a depth for ramming, then a num~ 
ber of rods should be laid in horizontally as before. 

Much time may be saved in molding if cores are made 
to fit the pockets next to the top plate and of a thickness 
of about 2 in. These cores should extend out to a dis- 
tance of 3 in. beyond the plate B. This prevents the 
green sand from breaking when turned over. The sand 
below the cores should be well vented to the coke bed 
and have a firm, even bearing all over. When no cores 
are used,, rods should be laid in near to the plate and the 
sand well rammed and vented to the coke bed. After re- 
moving the plate the edges should be well nailed before 
replacing the cover core. 

The flask is now filled to the plate B. This is left in 
place and sand rammed in and a surface made even with 
the top of pattern. When a special cover core is used, 
it should be put in place determined by the centre print 
and the edges marked in the sand and guide rods placed 
at the corners to ensure replacing to the proper position. 
The core is now lifted, the pattern drawn and the mold 
finished in this portion. The cover core is replaced and 
the remainder of the drag filled, rammed, and vented, 
ready to turn over. 



FOUNDRY PRACTICE 95 

When no special cover core is provided, an extra piece 
may be made for the pattern comin.cr to the edges marked 
C in the figure. This may be dra^^ n from the other side 
of the mold. In this case, after the surface is made even 
with the top of the pattern, the plate B is drawn and this 
piece is placed on the pattern with the centre print. Stock 
slab cores may be used to cover the mold in the place 
of the cover core. 

The drag is turned over, the parting made, and the 
cope rammed, having a gate at the centre of one side and 
a riser at another side. The large plate A is drawn first 
and the faces of the pockets finished. The front corners 
should be nailed with large nails and a few placed along 
the sides to prevent the sand from cutting, cracking off, 
or scabbing when the mold is poured. The ribs may be 
drawn separately and the centre scjuare last. The gate 
should be cut opposite the ribs, thus reducing to a mini- 
mum the liability of cutting. 

When the bottoms of the pockets overhang quite a dis- 
tance, it is advisable to put double-end chaplets between 
the core and the cover core. This takes the weight oi 
the core and prevents it from sagging when the flask is 
turned over. The lifting pressure mav be greater than 
will be held by the rods that are placed in the pockets. In 
this case, a plate of thin cast iron may be placed on thtr 
top of the pocket and a chaplet run through the cope 
to bear on this plate. The chaplet should be wedged 
only tight enough to prevent giving but not so as to en- 
danger cracking the green sand. Another manner of 
chapleting these pockets will be to use a double-end chap- 
let with plates on both sides or very large heads. The 
chaplets should be such that the distance between the 
two outer faces exactly equals the thickness of the plate. 



96 



FOUNDRY PRACTICE 



The plates on the chaplets are necessary, smce they bear 
on green sand and small heads would cut through with- 
out offering much resistance. 

Pulleys having a face of any desired width may be 
made by use of a pattern ring which is drawn up in 
molding to the width desired. The pattern consists of a 
pattern ring, as shown in Fig. 49, the arms with the de- 
sired hubs, and the core prints. Making the hub sepa- 




Fig. 49- 

rate from the arms allows putting any sized hub desired 
onto the one set of arms. 

The mold is made by the method of bedding in. The 
drag is placed on the bottom board and rammed with 
sand nearly to the height that the pattern ring should 
be placed. Riddled sand is put in to a height such that 
the ring will bed into it. The ring is then bedded down 
to such a distance that the width of the ring plus the 
distance A, Fig. 50, will equal the desired width of face 



FOUNDRY PRACTICE 



97 



plus the finish on the pulley. The sand is then rammed 
around the ring nearly to its top. This should be well 
vented all over before drawing up The ring is then 
drawn up about 2 in. by placing blocks at three or four 




4^ 

1. 






R 

mm 



I 



Fig. 50. 



points about the rim and extending above the ring an 
even height on each one. This keeps the ring even when 
drawn to a level of the blocks each time. In ramming, 
the sand must not be too hard about the ring or the 







^///////////j ^ 



VJ 






w 



^^^ 



UJ 



w^^ 



wwwwwwv^ 



m 



Fi!^^ c,i. 



iron will not run the rim full. Usually direct the ram- 
mer slightly away from the ring rather than toward it. 

The arms should be positioned when the ring has 
been drawn to half the width of the face of the required 
pulley. The arms are bedded in ar.d the parting made 



98 



FOUNDRY PRACTICE 



from the centre line of the arms having the sand between 
them come to a level of their top, giving the flask as 
shown in Fig. 51. This is for the purpose of not having 
a heavy body of sand hanging below the anchor. 

Sand is riddled over the parting and the anchor 
placed in position. The anchor as shown in Fig. 52 has 
the three nuts for the screw eyes which are for lifting 
the anchor. These screw eyes are left in place until 
after the cheek is rammed, then they are removed and 
the holes covered for ramming the cope. The outer cir- 




Fig. S2. 

cle of the anchor must be smaller than the inside of the 
ring: to allow for the contraction of the rim when cool- 
ing. Pieces should be put in to guide the anchor back 
to the same position after removing from the mold. 
These may be short cones or square pyramids. They 
are placed in two or three places between the arms and 
extending below the parting. They are fastened so as 
to ensure remaining firm in the anchor. These pieces 
are often called pulley feet. Around the edges of the 



FOUNDRY PRACTICE 



99 



anchor, nails should be placed to extend nearly to the 
pattern and firmly anchor the sand about the edges and 
the arms. The remainder is filled in, rammed and the 
pattern drawn until the parting is reached at the top of 
the drag. Two small gate sticks are placed on the hub 
for admitting the metal. The flask is ready for forming 
the parting as shown in Fig. 53, and for placing on the 
cope for ramming. 

The cope is rammed, having the twO' centre gates, a 
riser on the rim, and a vent opening from the cheek. 
The cope is lifted and finished. 

The vent gutter is cut around the outside of the 



\T>ea- ••■• .' - . - . • ., El.' > 




^v^ 



<fesip^;>^^;^;^^ 



O 



^ 




Fig. 53. 



cheek within about 2 in. of the ring and connecting with 
the vent opening in the cope. Slant vents lead to the 
gutter from all parts of the cheek. The outside is vented 
and led tO' the parting of the flask. In venting, the wire 
must not be forced deeper than the pattern ring, because 
it would break away the face of the mold. The pat- 
tern ring is drawn out and the screw eyes are replaced 
into the anchor and the cheek lifted out. The arms 
may then l)e drawn, giving the mold in parts as shown 
in Fig. 54. These may be finished and replaced, then 
the mold closed. 



t.ofC. 



100 



FOUNDRY PRACTICE 



A pouring basin should be built to allow pouring 
from the outside of the flask. The riser should be 
built to the height of the basin to avoid overflowing onto 
the flask. 



WZT. 



I .1 .. I 



:^.w 



r 



^ 




I 
I 



ifciiiiiiLi^ 



^ 






■V 



V 



\mmm////m/ ////mmT/}\ 



W 



rrr* 



'■ ''■■ ;;!•.'• yv:';;; \ W/^^(^* '- 









Fig. 54- 



The methods above given may be used for many 
forms of pulleys and sheave wheels. Double-arm pul- 
leys may be made in this manner by using a second an- 



FOUNDRY PRACTICE 



lOI 



chor to lift the cheek from 
the lower set of arms. The 
thickness of the rim may be increased 
by placing thin strips inside of the 
ring. In pulleys having wide face, it 
is best to anchor the sand in the out- 
side of the flask so that it may be lift- 
ed ofif. The face of the pulley, the ni- 
side of the rim, and the bottom of the 
rim may be finished easily when thus 
removed. 

P'or making sheave wheels by use 
of the pulley ring the grooves are 
made in core. Sheaves having from i 
to 3 grooves are made without using 
an anchor lift, by coping out 
the sand above the arms by a 
cope lift. In making a sheave, the 
method of procedure is the same as 
that of a pulley until the cope is lifted 
ofif. The sand on the outside of the 
pulley ring is then removed to a depth 
equal to the wadth of the cores which 
form the grooves. The centre part is 
finished as in the case of the pulleys. 
The cores are set about the cheek by 
use of strips which are the thickness 
of the metal below the grooves. The 
sand is filled in back of the cores, thus 
forming the outer face for the desired 
sheave. The strips are draw^n out 
and the mold prepared for closing. 





^o ^.-, o' 






^^U Y:- 




"^\ J' 




^N-^' 




t^""---'""^ 



.^. 





Fig. 55- 



102 



FOUNDRY PRACTICE 





::.:> 



nn 



Fi-. ^6. 



FOUNDRY PRACTICE 103 

Columns are cast with centre cores of such a size 
that the thickness of metal on the outside is that de- 
sired. Fig. 55 shows a column that is here taken to ex- 
plain some of the methods for making such forms of 
castings. 

The pattern used is shown in Fig. 56. It is a halved 
pattern longer than the desired casting and having the 
brackets loose. The drag is rammed in the customary 
manner. Facing is used all over the pattern when the 
length and thickness of metal will allow without cold- 
shotting the end away from the gate. The ramming 
must be even throughout its length, and is best made 
much harder than on smaller castings. The parting is 
made and the other half of the pattern is placed in posi- 
tion. Facing should be put on, the same as in the drag. 
It should be tucked beside the pattern to allow the gag- 
gers to be placed near the pattern. The cope is then 
placed on and an upset placed over the brackets to give 
sufficient depth of sand above the pattern. The gaggers 
are set in the cope. They should be long enough to 
reach nearly to the top of the flask and have a heel about 
6 in. long. The gaggers will be most effective when 
placed in the division having the heel extending parallel 
to the pattern and as close as possible. When pointed 
toward the pattern the edge is liable to break between 
the gaggers. It is only necessary to ram the cope one 
bar back of the collar. The gate is placed in this divis- 
ion and above the pattern. A riser should be placed 
above the large bracket. When the column has metal 
so thin that the iron is liable to be too cold when it 
reaches the bracket, it is preferable to have a gate at that 
end and pour with a bull ladle, thus supplying hot iron 
for the brackets. The cope should be rammed to an 



104 FOUNDRY PRACTICE 

even hardness the same as that of the drag and should 
be well vented. The bracket must be anchored as 
strongl}" as possible, having a gagger come between the 
bracket and the beam connection to prevent the metal 
from breaking through. The ramming around the 
bracket should be lighter than on the main bodv of the 
pattern. The pressure of the metal is not sufficient to 
prevent scabbing or blowing as in tlie other parts. The 
pattern should be held firmly to the cope by wood screws 
while it is being lifted off. 

In finishing the drag, it should first be vented by 
running the wire under the pattern from the sides of 
the flask and leading these vents ofif at the parting. 
Nails should be put in the corners near the collars and 



Fig. 57. 

the brackets. The joint may be wet with the swab, then 
the pattern drawn. The brackets still remain in the 
drag. A large nail should be placed in each corner of 
the bracket and two placed between the bracket and 
beam connection to prevent breaking through, as the 
metal fills one before entering the other. The brackets 
are drawn and the mold slicked. The cores shown at 
A, Fig. 57, are set in the collars and those at B are 
placed in the beam connection. These cores must be 
anchored to prevent lifting, due to the buoyancy of the 
metal. These cores may be held by nails so placed as to 



FOUNDRY PRACTICE 105 

resist an upward pressure. The end stop-off core shown 
at C is placed at the outer edge of the collars. This core 
is the same thickness as the met?.l of the desired col- 
umn. The chaplets are set in the drag, observing the 
precautions previously given. The number of chaplets 
depends upon the weight and length of the centre core. 
The centre core is placed in position and the end stop- 
off cores are placed on the top side. These small cores 
should be fastened so that they will not be pressed 
forward while ramming up the ends or be washed in 
by the iron. The gate comes through the end stop-off, 
hence it must be cut away back to where the metal enters 
from the cope and of a width to give the desired area of 
gate. 

The cope should be fmished similarly to the drag and 
the small cores set in the collars and the beam connection. 
The edges should be more firmly anchored than in the 
drag, so as to ensure holding when the flask is closed. 

The cope chaplets are set and the flask may be closed. 

In this form there is nothing to hold the metal from 
forcing the end cores out, hence there should be a divis- 
ion of the flask which may now be rammed with sand. 
The vents for the centre cores must be led off through 
the portion thus rammed. 

The pouring basin may be built and the riser raised 
to the level with it. The flask is clamped and chaplets 
properly wedged, thus it is ready to receive the metal. 

The strength of facing and the amount which may be 
used is entirely dependent upon the thickness of the met- 
al and the length of the column. Generally, when the 
metal is i in. in thickness, facingr- of a strenglh of from 
I — 10 to I — 16 should be used all over the pattern. 
Small columns up to 9 in. in diameter having metal less 



io6 FOUNDRY PRACTICE 

than I in. in thickness should not be covered all over 
with facing except when short. 

A column of 9-in. diameter and -^^^-in. metal, 18 ft. 
long may be made with facing i — 16 covering one-half 
its length. With facing stronger or covering more of the 
pattern, the iron is so cold before reaching to opposite 
end that it causes cold-shots or it will not run full. 

The manner of gating a column is dependent upon 
the size oi the column. For small and thin columns, a 
single gate at the end supplies the metal fast enough and 
enables forcing in case the metal is somewhat cold. In 
larger sizes, as from 10 in. up, or 9 in. having thick met- 
al, a gate on each side is more desirable. The metal may 
be led in by the end core or at the side by a runner and 
several gates. 

In making cast gears, it is very important to main- 
tain the exact form of the pattern and form all the teeth 
perfectly. The teeth are the most important part of such 
a casting, for if some are out of shape it will not run 
w^ith the gear meshing into it, hence the casting can not 
be used. 

The sand nmst be rammed into the teeth uniformly, 
and that as soft as v/ill resist the pressure of the metal. 
In small gears it can be done best by riddling the sand 
outside and throw^ino- it into the teeth until all are cov- 
ered, then ramming up the backing moderately hard. In 
large gears, the sand should be nailed or rodded while 
being rammed and care should be used to ram the teeth 
to an even hardness. 

When a gear is so small that facing can not be used, 
mix new sand with the old in a proportion of i part 
new sand to 3 parts old sand and use it for the fac- 
ing. In all other gears use facing varying in strength 



FOUNDRY PRACTICE 



107 



according to^ size. Generally use facing of strength of 
I part sea coal to 12 parts sand. Xever use plumbago 
or blacking on the teeth unless they are of large enough 
size to smooth it on with a brush or slick. The loose 
dust only roughens the casting and causes a dirtv, un 
even surface. 

The teeth of a gear can not be patched with tools as 
can corners and surfaces of a common mold. The form 




Fig. 58. 

of the tooth must be true, hence it is important that the 
pattern draw out well leaving the teeth without tearing. 
Some patterns have the teeth dovetailed into the body, 
then if any tooth does not leave the mold well it may 
be pressed down and drawn out separately. With other 
patterns, in case of patching being necessary the pat- 
tern must be replaced and the tooth reformed. 

The gate must always be placed upon the centre of 



io8 FOUNDRY PRACTICE 

a gear as the teeth would be very Hable to wash if the 
metal entered the mold from the rim. 

The method of procedure in making a gear from a 
solid pattern may be shown in mal^:ing a mold for the 
bevel gear shown in Fig. 58. The parting comes at the 
top or outer diameter of the teeth ?nd at the bottom of 
the hub at the short side of the arms. If a special follow- 
board or match is made for the pattern, the drag may 
be placed and rammed. In other cases, a match must 
be made on the cope. The cope is laid on a sand bed 
with the pins upward. Sand is filled in and rammed to a 
height that brings the parting line of the teeth even with 
that of the flask when the pattern is in position. The 
sand is rammed around the pattern until the level of the 
parting is reached. The parting between the arms is 
more easily made from this side than after the pattern 
is reversed; so this portion of the parting is made and 
parting sand put upon it. The drag is placed upon the 
cope, facing sand is thrown into the teeth until thev are 
well covered, sand is riddled over this, and the remain- 
der is filled and ranimed. The drag is vented, care being 
used not to strike the teeth of the pattern. The whole 
is turned over and the cope lifted while the pattern is 
held into the drag. The parting at the outside of the 
pattern is first made and the sand removed from the cen- 
tre down to the pattern. The pattern and adjacent sand 
are marked at some point by which to replace the pattern 
after it has been removed. The pattern is rapped to 
loosen the sand in the teeth, then drawn, carrving with it 
the sand above the parting previously made. The pat- 
tern is brushed clean and replaced, which completes the 
parting of the drag. Facing is riddled over the face of 
the drag and the cope is replaced. Soldiers are placed to 



FOUNDRY PRACTICE 109 

anchor the sand between the arms. These should ex- 
tend to the top of the cope to ensure sufficient strength to 
hold the sand firmly when the pattern has been removed. 
The gate stick is placed on the hub beside the core print. 
Facing is filled in to cover the pattern and rammed be- 
tween the arms with a hand rammer or rod that will 
tighten the sand evenly around the soldiers. The re- 
mainder of the cope is filled and rammed, care being 
used to ram around the soldiers without striking them. 
The cope is well vented and the gate stick removed with- 
out reaming or enlarging the hole, so that it may be re- 
placed after the flask is closed. A wood screw or draw- 
spike is placed in the hub through the gate. This is held 
and slightly rapped as the cope is lifted off. The rap- 
ping frees the teeth and the pattern is held firmly in the 
cope by lifting on the screw. The sand around the pat- 
tern and between the arms is patched and nailed where 
necessary. In large patterns the s?nd should be nailed 
before drawing the pattern, to help hold the sand from 
loosening or dropping while closing the mold. The sand 
at the edges of the pattern is moistened with the swab 
and the pattern drawn. In case any of the teeth were 
torn or damaged when the cope was lifted, the pattern 
should be replaced on the drag and the tooth reformed by 
ramming in sand with a small rod or nail. The pattern, 
tiien drawn, should give a perfect set of teeth as de- 
sired. Blacking may be put upon the cope and slicked, 
but it is preferable to leave the drag without blackening. 
The centre core is vented off at the bottom and has its 
top vent closed with sand so the iroi: cannot flow intO' it. 
The flask is closed and the gate stick replaced. A basin 
is built about it as shown in Fig. 47, so that the metal 
will not be poured directly into the gate, giving the addi- 
tional strain due to the metal dropping from the ladle. 



CHAPTER III 

Cores are bodies of sand in the mold for forming in- 
terior openings or holes in the casting. They may be 
made of green sand, dry sand or loam. Some patterns 
are of such form tliat the core is formed by the pattern. 
Generally the core is made separate from the mold and 
placed into it. When made in green sand it maintains 
the shape more accurately than dry sand, as the core is 
often distorted in drying. It requires more skill and 
tniie to form green sand cores than dry sand, hence the 
dry sand is used when the core is not simple or easily 
made in green sand. 

Dry sand cores may be made in a great variety of 
shapes to suit any case. They are made strong enough 
to resist the pressure of the metal, and may be anchored 
so as to be surrounded by metal, except an opening 
through which the gases escape. The use of cores great- 
ly simplifies molding in many cases. They may be used 
to stop off portions of the pattern, to prevent the neces- 
sity of many parts to the flask, to form irregularities and 
pockets that would be difficult to make with the pattern, 
and to form parts of molds instead of using a pattern, is 
in pit molding. 

A dry sand core is any form made in sand mixtures, 
dried until hard to allow handling, and used to form 
part of a niold. These cores may be made in any form 



FOUNDRY PRACTICE in 

from the plain to the very intricate and irregular cores 
required in some castings. When properly dried, the 
core becomes hard so it may be handled, and may be 
anchored by use of chaplets when necessary. The bind- 
er used in the mixture holds the sand together so that 
shapes may be easily made which would be very difficult 
to form in green sand. Dry sand cores may be made 
strong enough, to support the sand of portions of a mold 
or to resist great pressures from the metal. 

The proper venting of cores is a necessity. All core 
mixtures have a binder which holds the sand together 
when dried. This binder burns out when in contact with 
the molten iron, giving ofif gases which greatly increases 
that in the new sand used in the core. This formation 
of gas must have free relief within the core to prevent its 
forcing its escape through the metal. All mixtures 
for cores must be sufficiently open to give free passage 
for the gases. 

Cores having m.ctal against but one face will not re- 
quire any special vents. Small round cores require a 
vent through the centre. This should extend throughout 
its length. Cores having one face not covered bv the 
metal may be vented to this face by a vent wire to give 
the necessary relief to the gases. 

When the core is large or not easilv vented, coke, 
cinders, stones, or any very open material is placed in 
the core to collect the gases, which are led ofif by -m 
opening to the outside. Straight cores may be vented bv 
rods placed in the box when ramming the core. Crooked 
cores are vented bv manv methods. When lars^e enousfh 
to use coke without weakening the core, the vent ma^' be 
led out by placing coke through the centre of the crook- 
ed part to lead to the vent opening. Small crooked cores 



112 FOUNDRY PRACTICE 

may be vented in many ways. A roll of paraffine laid 
through the core when rammed will melt and run out 
when the core is dried, giving- the desired vent. Straight 
vents may be made to the bent portion of a core, and 
after drying these are connected by cutting away the 
core and laying in a string through one vent and extend- 
ing into the other, then covering with new molding sand 
or core mixture to reform the shape. The desired vent 
is left when the string is drawn out. 

Core sand will admit of hard ramming without caus- 
ing trouble when used. When rammed hard, the core 
will be stronger. The only precaution is to have the sand 
left sufficiently open to give free vent. All ramming 
must be done with the pein rammer until the last surface 
is reached, when it is butted off. If the butt is used be- 
tween the layers while filling a box, the surface made 
will not unite with the sand rammed on top, which 
makes a weak place in the core. If the sand is too wet, it 
should not be rammed so hard, for the pores close easier 
and form a solid cake which will blow when used in the 
mold. 

Cores may be greatly strengthened by putting wires 
and rods into them. The sand adheres to the rods so 
closely that it cannot be pulled out even tor a short dis- 
tance. This strengthens the core far more than the sim- 
ple bending of the rod, because it causes a tension in the 
rod, due to a tendency to elongate in an arc of a circle 
whose centre is at the surface of the core. This action 
is effective only to the amount necessary tO' crush the core 
at that centre. Small cores needing but little strength 
do not require rods. The strength due to the dry sand is 
sufficient where there is not much pressure or weight to 
be borne. 



FOUNDRY PRACTICE 113 

The rods necessary for a core depend upon the 
weight of the core and the strength it must have. Many 
cores are of such size or shape that they would not bear 
their own weight without rodding. Small and thin cores 
may be sufficiently rodded by heavy wire. All oil cores, 
except very small ones, should have rods to hold them 
to shape while green and to give extra strength when 
dried. The oil will adhere tO' the rod so that it becomes 
so firmly fixed that the core will break a wire before 
loosening from it. Larger cores are rodded in all direc- 
tions so as to tie the whole together firmly. The rods 
are bent to conform to the desired shape. 

Many cores recjuire to be hung in the cope. These 
m.ust have hooks or loops in them for their support. 
Other cores require the loop for handling or setting them 
into the mold. The loop is made of wire or rods of the 
necessary strength and is placed in the desired position 
m the core. Except when the core is small, the loop is 
anchored in the core by cross rods so placed as to brace 
the entire core from the loop. This gives strength to the 
core and makes the loop capable of bearing the weight. 

Large, heavy cores can not be safely rodded by loose, 
separate rods, as it does not give the sufficient strength. 
Special anchors, bars, or core irons are used in these 
cases. These core irons may be of cast iron, of wrought 
iron welded together, or may have cast iron bodies with 
wrought iron parts. These are so shaped as tO' carry the 
entire core firmly from the core iron. The hooks or nuts 
for screw eyes are made solid tO' the core iron for hand- 
ling. When the core has a large body part, loose bars 
and rods are used to bind the whole to the core iron. In 
many cases, the iron in it weighs more than the sand. 

Many cores are made in two or more parts and are 



114 FOUNDRY PRACTICE 

pasted together after drying. This is done in order to 
give a form to the core that will hold its shape before 
drving. Large round cores will sag and deform while 
green if made full, supported on a side. When made in 
halves the support comes upon the flat side, giving suf- 
ficient strength to maintain its shape. The making of 
cores in halves greatly simplifies the boxes used and 
gives the largest face outward to work from in making 
the core. 

The halves are pasted together after drying, to form 
the complete core. The paste used must be sufficiently 
i^trcng to hold the core when handled, when set in the 
mold and when the mold is poured. Wheat or rye flour 
wet with water to an even mixture forms a strong paste 
for this purpose. Graham flour, buckwheat flour, and 
fine meal each makes a paste that may be smoother but 
not so strong as wheat flour. 

In pasting a core the halves must come to a close 
bearing all over the surface of the joint. When the joint 
surface is warped or irregular, the halves may be rubbed 
together until a good bearing is obtained. When large 
or very irregular, the high places may be filed off or 
rubbed down with a brick. In some cases the halves are 
slightly thick, causing the core to be elliptical when past- 
ed. Therefore a core should be measured wath a caliper, 
and, when too thick, the joint should be rubbed down un- 
til the proper thickness is obtained. 

The sand and dust on the joint must be brushed off 
before putting on the paste, as the dust takes up the paste 
and prevents the solid joint desired. The paste should 
be spread over the portion forming the joint; the core is 
then put together and rubbed slightly, with pressure to 
give close union to the parts. 



FOUNDRY PRACTICE 115 

In pasted cores, the vent is taken off at the joint by 
cutting gutters in tlie joint surface and leading off 
through the print portion. These gutters must be kept 
open when the core is pasted. Sometimes it is advisable 
to lay into the gutter a rod, a string, or anything that 
may be drawn out after pasting. 

The paste must be dried in order to give it strength. 
If pasted while hot, the core will dry the paste. When 
f)asted cold, the core should be put in the oven until 
dried. 

If the core is properly pasted and dried, the joint will 
be as strong as any part of the core outside of the rods 
or anchors. 

All cores are baked, or dried, to drive off the moisture 
and harden the core. If a core is heated too much or 
left in the oven after it is dry, the buider burns out, leav- 
ing the soft burnt sand which crumbles and can not be 
used. When a core is dry it will give a clear ring when 
tapped with a stick or hammer. A convenient tool for 
sounding a core is the handle of a trowel. If the core 
is only partly dry the ring will be deadened. 

Cores may also' be tested for dryness by the odor. 
When green the flour, or binder, gives an odor similar to 
sour dough. When dry, no steam nor odor of green 
binder can be detected. 

The ovens for drying cores are of various kinds, chief- 
ly using direct heat although some have indirect heat. 
The indirect heat process is where the fire is in a separate 
chamber about the oven where the cores are dried. The 
direct heat process is to have the fire so placed that the 
heat and smoke pass directly through the oven into the 
chimney. 

Bv indirect heatinp-, the intensUv of the heat is more 



ii6 



FOUNDRY PRACTICE 



nearly even throughout the oven. By direct, the upper 
part is always much hotter than the lower part. Bv direct 
heating, the chimney flue opens from the lower part of 




Fig. 59. 



the oven at the end opposite the fire. This draws the 
cooler air from the bottom, which must be replaced by 
the hotter air from the upper part or from the fire; thus 



FOUNDRY PRACTICE 



T17 



it distributes the heat more evenly and reduces the loss cf 
heat passing into the chimney. 

The ovens for small cores are fitted with shelves 



vAy//////////// /////////////J/,^ 




Fi-. 60. 



Upon which the plates of cores may be placed. These are 
so arranged as to be convenient and accessible while the 




Fi-. 61. 

oven is hot. A convenient form of even for £m?Jl cores 
is shown in Fig. 59. In this oven the shelves are of the 
form of a semicircle hunq- at its centre. A door is fitted 



ii8 FOUNDRY PRACTICE 

to each side, thus closing the oven when the shelf is 
swung- out or in. 

The common forms of core ovens have the shelves 
fixed within the oven. The cores are placed upon the 
shelves through a door that opens in front of the shelves, 



Fig. 62. 

or the oven is so arranged that the coremaker may go 
inside the oven to the shelves arranged about in it. 
The ovens have the coke fire at one end while the 
gases are drawn off near the bottom at the opposite 



FOUNDRY PRACTICE 119 

end. This arrangement distributes the heat as evenly 
as possible but great variation is noted at various 
points of the oven. The shelves at the top nearest the 
fire are very hot, while the ones that are low at the oppo- 
site end are not hot enough to^ dry a core. This distribu- 
tion of heat is often of advantage, as those cores which 
must be dried quickly or slightly burned, as oil cores, 
may be placed on the hottest shelves, while other cores 
may be best dried in cooler portions of the oven. Cores 
that are replaced in the oven for drying the blacking or 
the paste may best be placed in the coolest parts of the 
oven. 

Fig. 60 shows an elevation and a sectional view of 
an oven for small cores. Fig. 61 gives detail of the same, 
showing its operation. The shelves for the cores are 
mounted on wheels at the back and are carried at the 
front by the trolley while the shelf is drawn out. Each 
shelf has its door at front and at back so that the oven 
is closed when the shelf is out or in. Any one may be 
drawn out by hooking the trolley to the handle, as in the 
case of the one in Fig. 61. The whole number may be 
drawn at once if so desired. 

A form of oven used extensively in shops making 
a special line of castings is one having a core-truck with 

shelves fitted for the special cores used. The truck is 
drawn out of the oven while it is loaded or unloaded, and 
is replaced in the oven while drying the cores. A form 
of such a truck is shown in Fig. 62. The oven for this 
purpose has its interior dimensions to suit the size of 
truck and its front end is fitted with some form of door 
that may be opened for removing the truck. The fire is 
made below the floor line at the back end of the oven and 
the gases drawn off at the front end near the bottom of 



120 



FOUNDRY PRACTICE 



the oven. A simple form of truck, or core car, is shown 
in Fig. 63. This is suited to large cores of any form. 
It is of advantage in jobbing shops having heavy cast- 
ings, because the cores there used vary greatly in size 
and form. These may be decked by placing rests on the 
platform and laying bars across. 

The mixture for a core may vary greatly to suit par- 
ticular conditions and different sands. The amount of 
binder necessary is that which will form a hard core 
when dry and which will not be too close, nor burn out, 



n 



Fig. 63. 

allowing the metal to enter into the core forming rough- 
ness on the casting. 

The mixture given in Receipt No. I is well adapted 
to small cores made on the bench. With some sands 
this percentage may be increased. With large cores, the 
percentage may be reduced to that of i part flour to 12 
parts sharp sand. 

The core may be strengthened in heavy work by 
mixing a percentage of new molding sand with the 
sharp sand. The mixture given in Receipt IV gives a 



FOUNDRY PRACTICE 121 

strong core for large work, as arm cores for fly wheels, 
etc. 

When a core is nearly surrounded by metal, it is nec- 
essary to have a strong core with as little enclosed gas as 
possible. Receipt II forms a core which is very strong 
and which may be easily vented since it is nearly an oil 
core. This mixture while green will not have much 
strength so that it may be difficult to dry without its los- 
ing the form desired. By adding a small percentage of 
flour, the green core has more strength and has as much 
strength when dry. 

Receipt III will give a hard oil core which has great 
strength for its size and will not blow when the metal 
covers the greater percentage of it. This is of greatest 
value in making thin split cores. The core should be 
slightly burned after drying, to give an open texture 
without injuring its strength. 

The mixture given in Receipt V is for making cores 
by the machine. The proportions may be varied to give 
the best core with the easiest operation of the machine. 
If the sand is too wet or has too much flour, it will stick 
to the tube, thus clogging the machine. If too dry, the 
machine will not compress the sand sufficiently to give a 
strong core. These cores are improved by burning slight- 
ly while drying. 

Receipt I. — 6 parts fine sharp sand, i part flour, wet with 
water. Vary the above, to suit conditions, to 12 parts 
sand tO' i part flour. 
Receipt II. — 2 parts fine sharp sane, i part new mold- 
ing sand. To 75 parts of mixture add i part of lin- 
seed oil or core compound. 
Receipt III. — Add oil to the sharp sand until it becomes 



122 FOUNDRY PRACTICE 

saturated, or will show slightly on the finger-nail when 

pressed into the sand. 
Receipt IV. — 3 parts of sharp sand, i part new molding 

sand, I part flour to 8 parts of the mixture. Wet with 

water. 
Receipt V. — 10 parts of medium grade sharp sand, i part 

flour. To 75 parts of mixture add i part linseed oil. 

Moisten with water until the whole adheres. 
The face of the core which is to be covered with iron 
is coated with blacking to give a smooth face and prevent 
fusion with the sand. 



Fig. 64. 

The mixtures of blacking for dry sand molds give a 
very good mixture for large cores. Cheaper mixtures 
give good results on small cores. The simplest blacking 
is the prepared core blacking or black lead mixed with 
water to the desired thickness. A better mixture for 
light cores may be made by use of the following receipt : 
Mix 6 parts charcoal blacking and i part graphite. Wet 
with molasses water or sour beer. 
Hay or straw is twisted into ropes in order to form 
an open band which may be placed v/here it gives 
strength in holding the sand, besides providing a free 



FOUNDRY PRACTICE 123 

escape for the gases. It is used chiefly in loam work 
or in cores where the core barrel is used. It is some- 
times used in molds to provide a vent passage from 
parts of the mold. 

The rope is made by twisting by hand or by the use 
of a hay-rope twisting machine. Fig. 64 shows a ma- 
chine for twisting hay rope and winding the rope upon a 
reel for convenience in handling. 

Long round cores are often made upon a core barrel 
to give them strength and to lessen the amount of core 
sand necessary tO' make the core. The barrel is a pipe of 
wrought or cast iron having holes through its surface to 
allow the free escape of the gases from the outside to the 
inside of tlie barrel. When made of cast iron, the outer 
face has projections and unevenness for holding the core 
sand to the barrel. Wrought iron barrels may be the 
plain pipe with vent holes drilled through at frequent in- 
tervals. 

The core barrel is used for making the centre core 
for columns, pipes, cylinders, and round cores of that 
type. The core made on the core barrel is much lighter 
and easier to handle than a solid sand core. The barrel 
gives the core greater strength than the rods, especiall) 
in cores of small diameter. The amount of core mixture 
used to make the core will be that necessary to form a 
shell over the barrel, while the other core must be solid. 
The saving of core mixture is often worthy of consider- 
ation. 

In order to form a core on a core barrel, the barrel is 
wrapped with hay or straw rope, then covered with loam 
or core mixture to give the desired diameter. The barrel 
is placed upon supports at each end and fitted with a 
crank so that it mav be rotated. This mechanism with 



124 



FOUNDRY PRACTICE 



the strike or sweep for forming the face of the core is 
called a core lathe. The end supports may be a frame 
having a notch in the upper side for holding the barrel or 
centre shaft which supports the barrel. The frame ex- 
tends horizontally to support the sweep. The barrel is 
placed upon the supports and rotated by the crank, while 
the core maker guides the hay rope onto it until the de- 
sired length is covered. The surface is then covered with 
the core sand and compressed to give the necessary 
strength. The sweep is placed upon the supports and 
the surface swept up by rotating the barrel. The sweep 
is moved toward the axis until the desired diameter of 



U 



TJ 




Fig. 6S. 



core is formed, when the surface is slicked ready for dry- 



msr. 



The procedure in making cores varies to quite an ex- 
tent in particular cases. The general principles always 
apply and the variations are mainly in rodding, venting, 
and mixture of sand best suited to the special core de- 
sired. It being impossible to give examples and explana- 
tion to cover every case, a few examples are given to il- 
lustrate the principal methods of making cores. 

All small cores that do not require rodding are made 
by ramming the box full of the core mixture and venting 



FOUNDRY PRACTICE 125 

toward the print side of the core. It is then ready to put 
on the plate for drying. 

Fig. 65 shows a box for maiving a round core. The 
method of making such a core is here given. The two 
parts of the box are clamped together and placed on 
end upon a smooth board or plate. Some core sand is 
placed in the box, then the vent wire is pressed into the 
centre. The sand is rammed around the vent wire with 
any convenient rod. This form of core will stand to 
be rammed quite hard. The ramming is continued while 
the sand is added in small amounts until the box is full. 
The top is slicked even with the box and the vent wire 
withdrawn. The box is inverted and the lower end 
slicked even with the box if it were not so left bv the 
piece it rested upon. The clamps are removed from the 
box. The core is loosened by rapping the box on the 
sides. 

Half of the box is lifted off from the core, leaving 
it in the lower half. This is turned out upon the plate 
by the following method. Place the part containing the 
core on the plate. With the fingers of both hands gentlv 
resting on the core, raise the box with the thumbs so 
that it turns over until the fingers nearly touch the plate. 
Gradually withdraw the fingers allowing the core to slide 
down to the plate evenly and gently. The core may be 
moved by placing a straight side of the box against it 
and moving the box until the core is in the desired place. 

The object of placing the vent wire before ramming 
is to keep it in the centre of the core. When the core is 
short, it may be quicker to ram the box full, then press 
the vent wire through, using care to keep it in the centre. 
When the core is long and must bear a pressure it should 
have a rod put in while ramming. Many core makers 



126 



FOUNDRY PRACTICE 



press the rod in after ramming the core by running the 
vent wire through first. This is a very poor plan, as 
the sand may be loose around the rod, so that it does 
not strengthen the core, or it may close the vent, causing 
trouble in that way. In order that a rod should strength- 
en a core, it must be solid into the sand as a part of it. 





Fig. 66. 

Many cores are made in a skeleton box with a strike 
or former. This form of box is very cheap to make 
and a core may be readily made in it. Fig. 66 shows 
such a box with its strike. This niakes one-half of the 
core, which when pasted forms the core shown in Fig. 



FOUNDRY PRACTICE 



127 



f>y. This core is 18 in. in diameter at the base, 4 in. at 
the top, and 30 in. long. The core rests on prints at each 
end, so must be sufficiently strong at the small end to 
sustain the weight of the core when placed in the mold. 

The box is placed upon a plate having a smooth face. 
A little dry sand is sprinkled over the plate to prevent 
the core from sticking to it. Core sand is then filled in to 
a depth of about 2 in. A rod about 26 in. long is wet 




Fig. 67. 

with paste and placed in the centre of the box and bed- 
ded into the sand. Sand is then filled in and rammed 
with the pein until it is nearly of the required size. The 
last sand is butted onto the surface making a solid core 
to strike off. A few vents are directed to the centre of 
the lower side from the larger portions of the core. 

The face of the core is struck off by maintaining the 
notch x\ against the end of the box and always keeping 
the face of the strike directed radially to the centre 
line of the core. The surface is slicked and brought to 
an even smooth surface. The box is then drawn from 
the core. 



128 FOUNDRY PRACTICE 

Tlie second half is made in the same manner. The 
two halves are blackened with a niedium thick mixture 
of the blacking and are put in the oven and dried. They 
are then placed together and rubbed to give a good bear- 
ing. The two ends should be tried with a caliper for 
the correct diameter. When too large, the core should be 
rubbed down until the proper diameter is reached. The 
halves are then taken apart and the vent gutter is cut 
through the centre the full length of the core and on 
both halves. This should connect the vents previously 
made through the body of the green core. The sand 
and dust are removed from the face of the joint and 
paste is put upon one-half of the core. The paste should 
be strung along in a thick, narrow tow midway between 
the edge and the vent gutter. If spread thin over the 
surface it may not give contact at a portion of the face. 
When left on thick, it squeezes out when the core is put 
together and makes a firm joint. Care must be taken 
to prevent filling the vent gutter with paste when the 
core is put together, thus closing tne vent passage. 

The half without the paste is then placed upon the 
other and the two pressed together with a little rub- 
bing to force the excess of paste out of the joint. The 
openings still left at the joint on the sides of the core 
should be filled with stiff blacking if small, but when 
large pieces may have broken off, the face of the hole 
is covered with paste and core mixture is pressed in 
to fill tO' the desired surface. The face of the joint may 
be smoothed by going over with wet blacking on a 
swab or brush. After the paste and blacking are dried, 
the core is ready for use in the mold. 

The skeleton box and strike niay be made use of 
under greatly varying conditions. AVhenever there is a 



FOUNDRY PRACTICE 129 

core or portion of a core that may be struck into the 
desired form with a strike, the skeleton box may be 
made use of. The most general use is found in making 
round cores, especially of large sizes. The strike in 
this case is straight. The strike or former is also used 
to move lengthwise of the core instead of crosswise or 
around the core. In making cores for water pipe specials, 
as ells, tees, etc., a former is made of the desired semi- 
circumference, and the core is shaped by guiding upon 
the skeleton box or upon a core plate made to the de- 
sired outline. 

The head stock core, shown in Fig. 36, is made in a 
half box having loose pieces to form the recesses for 
the bearings. The halves are made the opposite way by 
having reversible parts to the one box or by having 
two separate boxes. The preferable way is to have the 
one frame with the loose piece to m.ake .the desired parts. 
This core is thick enough to have the necessary s^ength 
without rodding. The box is filled about 4 in. with core 
sand and rammed with a small pein rammer. The 
loose pieces are put in place and the core sand is 
bedded under and around them, care being used to 
ram it sufficiently and tO' keep the pieces in their proper 
position. The remainder of the box is filled, rammed 
and butted off. The face is struck off and surfaced with 
the trowel even with the top of the box. Vent gutters 
are cut to lead off at the print side. Slant vents are 
directed from the gutter under the loose pieces and 
into the body portions of the core. The loose pieces are 
then drawn from the box. The face is slicked, if nec- 
essary, then the opening is filled with molding sand of 
the usual temper for molding. This supports the over- 



130 



FOUNDRY PRACTICE 



hanging portion of the core while it is green and is 
easily removed when dry. 

A core plate is placed on the box and the box is 
turned over, holding the two firmly together. The box 
is rapped on all sides, then drawn vertically with light 
rapping on the outside of the box. The core is slicked, 
then dampened on the face with water and placed in 
the oven for drying. The face of the core is dampened 
to form a liarder skin when the core is dried. If too 
much water is put on at any spot, it washes away the 
binder leaving the face soft and rough with loose sand. 
The water may best be sprinkled on the core by wetting 
a brush and throwing the water froni it by holding the 




Fig. 68. 

hand and striking the brush against it with the other 
so that the jar throws the water. With a little prac- 
tice the core may be dampened just as desired by this 
method. A more convenient method of dampening the 
core is by use of the spray can or spraying bellows. 

The core is blackened, pasted, and finished as in 
the previous case, giving the completed core desired. 

A simple form of core using a special anchor may 
be found in making a large round core for a cylinder. 
Fie:. 68 shows an anchor for half of a core for a cvlinder 
48 in. in diameter. The anchor was made for a skeleton 
box. 



FOUNDRY PRACTICE 131 

The method of making the core may be explained 
briefly as follows. The box is placed upon a smooth, 
even plate easily accessible to the drying oven. The 
core sand is riddled evenly over the surface enclosed by 
the box to a thickness of about i in. The anchor is 
coated with flour paste or clay wash and placed in po- 
sition within the box. When the anchor is light it should 
be rapped down, then tucked all around to ensure an 
even, hard core under the anchor. The core sand is 
filled in and peincd finnly. Each layer should be but 
3 or 4 in. in thickness. After the anchor is covered to 
a thickness of about 2 in. the core is vented, leading 
toward the centre. A bed of coke is laid through the 
centre about 10 in. wide and 5 in. deep. Long rods 
are laid in near the wrought iron bands to firmly tie 
the sand between them. Rods are placed at the outer 
rim at intervals of 2 or 3 in, as the core is rammed. 
This size of core must be very solid in order to have 
sufficient strength to carry its own weight. 

While ramming, it saves time to fasten pieces onto 
the outside of the frame of the box to hold the core 
to the desired form. Without the pieces on the sides, the 
sand will crush out or expand at the bottom while ram- 
ming on the upper portion of the core. When the ram- 
ming is completed, the pieces are taken off the side and 
the entire core is vented to the coke centre. It is then 
struck off and the surface slicked to a smooth, even face. 
This anchor is provided with nuts into which screw 
eyes are placed for handling the core. The screw eyes 
are left in while ramming the core. The rods must be 
kept at least an inch from the screw eye so that th.:y 
will not be loosened when the screw eye is removed. 

The box mav be taken from the core and the re- 



132 FOUNDRY PRACTICE 

mainder of the core is slicked. Wet blacking is put even- 
ly over the surface. The blacking should be as thick 
as will spread readily and evenly. The core is then 
ready to dry. 

The other half has the nuts in the anchor offset from 
those in the first half, so that openings may be left 
through the entire half directly over the nuts in the pre- 
vious one. When the core is together finished, the screw 
eyes are fastened into the lower half of the core. The 
second half is made the same as the first except that 
round sticks are placed exactly in the position of the 
nuts of the first half. 

The core should be pasted while one-half is hot 'n 
order to dry the paste. The crack at the parting is filled 
with hard blacking or core sand, then coated with black- 
ing and dried by replacing in the oven or by a fire built 
around the core. 

The same core mav be made in manv other wavs, 
dependent upon the appliances available. The principles 
are similar in making all cores having special anchors 
All large cores must have special frames or anchors 
to give them strength. The forms of these anchors and 
the fitting for handling are nearly as various as the 
different cores in which they are used. 

In many cases the core is nearly submerged in iron 
when the mold is poured. These cores must be made 
so as tO' give very free vent to the gases in order to 
prevent blowing in some part. Where the core is large 
enough to easily collect the gases at its centre and 
lead them off through the print, the core may be made 
very similar to other cores. When the core is thin or 
so shaped that proper venting is difficult to obtain, the 



FOUNDRY PRACTICE 



133 



mixture should be such as to give a hard core with as 
httle gas as possible. 

The core shown in Fig. 69 is for forming a pocket 
in a crank disk which will be filled with lead as the 
counter weight for balancing the engine. The core here 
shown is a semicircular segment whose inner radius 
is 10 in. and outer radius 21^ in. The thickness is 
3 in. with 4 openings on one side 2^ in. in diameter. 
Ihis core is surrounded except for the openings through 
which the vent is led off. 

To make this core, the mixture given in Receipt No. 




/ — ■ 



Fig. 69. 

II proved very satisfactory. Procure 4 pieces of wrought 
iron pipe i in. or 1}^ in. in diameter and 4 in. long. 
Burr out one end so that the pipe bulges bell-shaped. 
Cover the pipe well with linseed oil, then place in the 
centre of each print or opening and fill in with the core 
sand. This pipe extends to the centre of the core where 
the gases are led ofif. The entire box is filled in a little 
over an inch in depth with the core sand and rammed. 
Wires are laid in to bind the core. These wires should 
be of such a size as to hold the core and still be easy to 
remove from the casting through these small openings 



134 FOUNDRY PRACTICE 

of 2^^ in. in diameter. These wires are laid in length- 
wise of the core, placing one near the onter circle and 
one near the inner, while one is placed about an inch 
away from the pipes on either side of it. The wires are 
bedded into the sand now in the box. Sand is filled in 
to the level of the top of the vent pipe. 

\'ent gutters are laid out just inside of the outer 
wires, with a similar one through the centre to connect 
the vent pipes. Cross gutters connect the ends and join 
the outer gutter at each of the pipes, and similarly mid- 
way between the vent pipes. These gutters are made 
to a depth of about ^ in. below the centre. Fine coke 
is laid in the gutter to a depth of about i in. The 
coke taken is that which will pass through a No. 2 rid- 
dle and will not pass through a No. 6. The coke 
is then covered with coarse sharp sand or fine gravel 
to prevent the core sand filling up the openings between 
the coke. This should bring the sand above the top 
of the pipes. The pipes should be filled with waste or 
anything to prevent the sand from filling them, and the 
waste may be removed after the core is finished. The 
top of the pipes is covered with coke to connect freelv 
with the vent gutters. This is covered with sand the 
same as the gutters. Core sand is filled in to the top 
of the gutters and rammed. Cross wires are laid at 
distances of about 4 or 5 in. to^ bind the core togethet. 
A little more sand is filled in over the entire surface ot 
the box and long rods laid in as before. The remain- 
der of the box is filled and rammed. The top is struck 
off even with the box and the face slicked smooth with 
the trowel. Parting sand or dry sharp sand is dusted 
over the face to prevent its sticking to the plate. A 
straight plate is clamped ontO' the core box and turned 



FOUNDRY PRACTICE 



135 




SJ3 



136 FOUNDRY PRACTICE 

over, when the box may be removed giving the core as 
desired. 

Oil or core compound readily bakes onto a plate so 
as to stick the core to it. When making those cores, 
something must be put onto the plates to prevent the oil 
from fastening to the plates. Other cores separate read- 
ily from the plates after drying. 

The round cores of various sizes are used in so many 
different castings that all foundries keep a supply of 
each size in stock. These may be cut to the length de- 
sired in any case. This is a much cheaper method 
than making special cores for each pattern used. The 
boxes for cores up to 4 in. in diameter are made sim- 
ilarly to those shown in Fig. 65, and of a standard length. 

Machines have been invented for making these stock 
cores which greatly reduces the cost of labor. These 
machines are made with changeable parts for making 
cores up to about 2 in. in diameter. There are several 
manufactories making machines for this purpose. The 
Hammer core machine shown in Fig. 70 is fitted to 
make cores from yi in- to 2 in. in diameter. The mix- 
ture is placed in the hopper and by turning the crank 
wheel, the mixture is forced through the tube of the de- 
sired size by a bit directly back of the tube. Tliese 
give a core vented in the centre throughout its length 
and of an even hardness. The ramming is dependent 
upon the friction of the sand on the tube through which 
the core passes. 

The mixture that makes a very good core is one with 
oil and flour as a binder. 



CHAPTER IV 

Dry sand molds are made similarly to green sand 
mold, using special facings. The mold is blackened with 
a wet blacking and slicked smooth, then dried in an 
oven or by special drying apparatus. The surface after 
drying is hard, similar to a brick. This gives a surface 
that can withstand great pressures where a high head 
is necessary in casting. The dry face coated with the 
blacking prevents fusion of the sand and thus gives 
a smooth casting. Hence where it is desirable to have 
a smooth casting or when the head pressure is great, dry 
sand or loam molds are used. 

The mixture used next to the pattern in dry sand 
work is called the dry sand facing. That used to 
fill in between the facing and the flask is called the 
backing sand. Old molding sand forms a good backing. 
Dry sand facing comprises a mixture which will become 
hard and strong when dried and still be open to allow 
free escape of the gases. The mixture for the dry sand 
facing is dependent upon the sand obtainable in the lo- 
cality. A sand too strong with clay gives the hard, 
strong face to the mold but will not allow the gases to 
escape. Where the molding sand is of a fine quality and 
quite strong with clay, Receipts Nos. i and 2 will make 
a good facing. The proportion of sharp or lake sand 
may be varied where the facing is found to be too close 
or too open. 



138 FOUNDRY PRACTICE 

Receipt No. i. Mix i part new molding sand, i part 

old molding sand, and 2 parts sharp or core sand. To 

30 parts of sand add i part flour and i part sea 

coal. Wet with water. 
Receipt No. 2. Mix 4 parts of molding sand with i 

part sharp or lake sand. To 30 parts of sand add 

I part of flour. Wet with clay wash. 
Receipt No. 3. Mix i part of molding sand with i 

part of bank sand. To 30 parts of sand add i^ 

parts of sea coal and i part of flour. Wet with clay 

wash. 

Dry sand may be rammed much harder than green 
sand. The facings are more open and the moisture is 
evaporated from it before casting. The ramming should 
be even, because unevenness may cause trouble similar 
to green sand though not so readily. Hard spots in 
the face of a dry sand mold will cause a scab on the 
casting. 

The importance of venting dry sand must not be 
underestimated. After the mold is dried there is no 
moisture tO' form steam as in the green sand mold. 
The other gases are still formed at the face of the cast- 
ing and must be carried away or the casting is liable 
to blow or scab. When there is 6 in. or more of sand 
between the casting and the flask no venting is neces- 
sary. When less than 6 in. there is not sufficient space 
to relieve the pressure unless there are holes in the flask 
for release or vents for carrying off the gases. 

As the body of sand increases, the pressure of the 
gases decreases, hence the smaller the body of sand 
the greater the necessity of vents. Large bodies of 
sand give relief to the pressure through its openings 
or porosity. It literally holds the gases without in- 



FOUNDRY PRACTICE 139 

creasing the pressure to a dangerous degree. Pockets, 
corners, flanges, and similar projections require venting 
and provision for conducting off the gases, but not so 
extensive as in green sand molds. 

In green sand, when the joint comes together closely, 
it may compress slightly without damage when the flask 
is clamped. In dry sand, the hard surface will not admit 
of any compression without breaking away. This is 
avoided by cutting away the joint slightly at the edge 
of the pattern before or after drawing. This leaves 
a fin on the casting which may be chipped off. The 
edges where cores bear should be similarly treated. 
This fin should be from y^ in. to yl in. in thickness and 
should slope back about 3 in. The maxim *Tt is better 
to have a fin than a crush'' should be remembered in drv 
sand Avork. 

The finishing of dry sand molds gives the face which 
causes the casting to peel. After the pattern is removed 
the face of the mold is dampened with molasses water 
or beer wash. This makes the facing stick together firmly 
and gives a smooth compact surface when slicked. 
The flour in the facing makes it rather pasty so it can 
be shaped more easily than a green sand mold. The 
entire face is slicked with the tools before blackening. 
Any part torn by the "pattern may be patched similarly to 
a green sand mold. The face of the mold may be slicked 
much harder than in a green sand mold. The sand is 
much more open and held together by the flour so it will 
not scab so easily as green sand. 

The blacking is put upon the dry sand mold to close 
the pores of the sand and give a smooth surface that 
will peel from the casting. The mixtures given below 
have yielded very good results. The proportions may 



140 FOUNDRY PRACTICE 

be varied to suit the qualities of the ingredients and to 
give better results in particular cases. When the black- 
ing cracks or peels upon drying, the body has been put 
on too heavy or there is too great a percentage of clay 
w^ash. 

Receipt No. i is used for light castings or where 
the thickness of metal is less than 2 in. Receipt No. 2 
is better for heavy or thick castings. Receipt No. 3 is a 
very simple mixture which gives good results on small 
or thin castings. 

Receipt No. i. — j\'Iix i part charcoal blacking, i part 
Lehigh l)lacking, 2 parts plumbago. Wet with mo- 
lasses water or sour beer. 
Receipt No. 2. — Mix 8 parts charcoal blacking, 8 parts 
plumbago, i part thick clay wash. W^et with sour 
beer and allow to stand 2 or 3 days before using. 
Receipt No. 3. — Mix a clay wash from red clay of a 
thickness that will color the hand when dipped into 
it. Add plumbago' until it becomes of the thickne-s 
desired. 
The molds are dried by heating sufficiently to drive 
off the water from the sand. This is accomplished in 
many different ways to suit the conditions. The best 
method is to dry the mold in an oven. The oven for 
this purpose is similar to the core ovens which admit 
a core car. The molds are put on the car for placing 
in the oven. The temperature is ke]>t between 500° 
and 600° F. This will not burn the face of the mold and 
dries it very rapidly. 

Some molds are dried by injecting hot air. The mold 
IS closed with the pipes from a heater projecting into it. 
All the openings and the parting are sealed with clay 
tO' resist the air pressure. The air is kept under a small 



FOUNDRY PRACTICE 141 

pressure which forces it out through the sand and vents. 
The heat dries the sand giving the desired result. One 
form of apparatus to accompHsh this would consist of 
a heater or large stove having a coil of pipe in the place 
of the lining. The air is forced through this by a 
root blower. The blower is driven by a motor or belted 
from a shaft. The coil in the heater is connected to the 
mold by a pipe. The heater should be as close to the 
mold as convenient to reduce the cooling of the air be- 
fore reaching the mold. 

Another common method of drying is to use the fire 
pot. A charcoal fire is built in a fire pot and lowered 
into the mold. It should be kept at equal distances on 
all sides from the faces to be dried. The fire pot should 
conform to the general shape of the mold. This gives 
unequal drying on an irregular-shaped mold. When 
carefully followed very satisfactory results are obtained. 

The face of the parting is slicked down before dry- 
ing, so that the sand does not touch when the flask is 
closed. It is therefore necessary to place upon the face 
of the parting something that will seal this opening and 
hold the metal. A stifif dough made of flour and water. 
then rolled out into long strings, serves the pu^'pose. 
The dough will flatten without damage tO' the mold, when 
the two parts of the mold come very near together. 
These strings, often called noodles, are placed around 
the edge of the mold and over cores which should bear 
on the cope. 

Dry sand may be employed without the use of fac- 
ing. It is claimed by many of the best foundrymen that 
it is unnecessary to use flour and sea coal in the facing 
for a dry sand mold where a good blacking is used. The 
object of the fiour is to make the face hard when dry. 



142 FOUNDRY PRACTICE 

as a core. The sea coal is to prevent fusion of the sand 
and to peel the casting. For the medium-sized cast- 
ing in dry sand the facing used is i part new molding 
sand with i part old molding sand wet with clay wash 
and riddled through a No. 6 riddle. The backing may 
be of the coarsest heap sand. The blacking for the 
mold is made from Receipt No. 3. Castings made by 
this method have been found to peel and to leave as 
smooth and bright a surface as any dry sand mold. 

In many cases where previously dry sand molds 
were used, it is found as satisfactory to only skin-dry 
the mold. The mold is handled in the same manner 
as a dry sand mold, but the drynig is continued only 
long enough to dry the sand for a depth of about 2 in. 

Some kinds of sand which are quite strong with clay 
do not require the flour used in the dry sand facing, but 
hold Avell when moistened with clay wash, molasses wa- 
ter, or beer wash. Generally the same facing is used as 
in dry sand molds. 

A skin-dried mold has the hard surface but the back- 
ing is still soft. This increases the danger of crushing 
when closed and of the cutting of the metal when poured. 
The mold should be cut away at the parting and the 
entire joint slicked down slightly to ensure the bearing 
on the flask instead of on the sand. The dried crust will 
separate from the green backing much more easily than 
a dried mold would break. When a casting is so gated 
that it would be liable to cut if the sand were green, it 
should be well nailed in front of the gate before skin- 
drying. 

Tlie face of the mold is finished, 1)lackened, and 
slicked the same as in dry sand. Ihe blacking- may be 



FOUNDRY PRACTICE I4J 

put on dry, then moistened with molasses water; or, bet- 
ter, the wet l^lacking mixture may be used. 

A mold is skin-dried by the same method used for 
dry sand molds. For slightly drying the face of small 
molds, gasoline may be sprayed on the surface and 
burned oft", giving a hard face. This may be used with 
some kinds of sand in the common green sand mold, 
giving the casting the appearance of coming from a dry 
sand mold. It gives a smoother casting in small work 
than the wet face. 

Many castings can not be easily made in a flask, owing 
to their size or form. These are made into the floor 
with a cope to cover a part or the whole. This division 
of molding is called pit molding. Fly wheels, large 
sheaves, and large gears are made in this wav more 
easily than in the drag of a flask. Many large cast- 
ings that might otherwise be made in a flask are 
bedded into the pit when there is no flask at liand. 
It is much cheaper to bed the pattern into the floor than 
it would be to make a flask when only one casting is de- 
sired. Some molds are subjected to an intense down 
and side pressure when the metal is poured. It would 
require a very strong flask to withstand this stress, hence 
it would be very expensive. If placed in the pit, the 
sand is rammed hard to the adjoining ground, hence the 
pressure is resisted except that on the cope which 
must be provided for by weights or the cope must be 
bolted to anchors in the ground. 

Since there is no opening at the bottom, as in the 
case of a flask, for the escape of the gases, provision 
must be made to carry these off from the bottom of the 
mold. Below the mold at a depth of about 2 ft., a layer 
of coke or cinders is placed to collect the gases. This 



144 



FOUNDRY PRACTICE 



oo oooooo 

cooooooo 

—— 






o 
o 




D 









Fig. 71. 



FOUNDRY PRACTICE 145 

coke bed is connected to the surface by a vent pipe. All 
the vents from the lower portion of the mold extend 
through to this coke bed which gives relief to the gases. 

To make the coke bed the pit is dug out about i^^ 
or 2 ft. deeper than the mold would require. It is 
then leveled oil and a layer of coke of about the size of 
an egg is put in to a thickness of 2 or 3 in. The coke 
is covered with hay, straw, or gunny sacks to keep the 
sand from packing solid around the coke. A pipe of 
ample size to give free vent to the bed is placed at the 
outside to connect with the surface. The lower end of 
the pipe rests on the coke and is so covered with coke 
that the sand can not enter the pipe. The sand may 
now be filled in to form the mold above. 

Making castings by use of sweeps, in the place of 
patterns, is being extensively practiced where but a sin- 
gle casting is required. The time required for making 
such a mold is greater than that required where, a pat- 
tern is used, but the expense of making the pattern is 
saved, except for forming the sweeps which is very 
slight. 

A simple form of the necessary rigging is illustrated 
in Fig. 71. The socket A is a cast base having a tapered 
hole in the centre for holding the spindle. The spin- 
dle B is made of steel or cast iron, and is uniform in 
diameter, having its lower end tapered to fit the socket. 
A collar is fitted to the spindle and has a set screw for 
fastening it at any point. This carries the sweep arm 
at the desired heio:ht. The revolvino- arm D is made of 
cast iron, bored to fit the spindle and having slots for 
bolting the sweep and allowing adjustment. The sweep 
is made of wood having the special shape for the desired 
casting. 



146 



FOUNDRY PRACTICE 



The process of fomiing a green sand mold by use of 
a sweep ma5^ be noted in making ? cover as shown in 
Fig. 72. A hole is dug intO' the floor and the socket 
is bedded in so as to hold the spindle plumb. A coke 
bed is formed around it with the vent pipes leading to the 
surface. Sand is filled in and rammed to a level shown 





Fig. 72. 

by line MN, Fig. 73. This is well vented to the coke 
bed with a ^ in. wire. Facing sand is filled in and 
rammed to the height that it is to be struck off and to 
approximately conform to the line ACB of the top of the 
cover. The sweep arm is placed upon the spindle above 
the collar C. The sweep is made to conform exactly 
to the upper face of the cover. It is fastened to the arm 



FOUNDRY PRACTICE 



147 



so as to have the outer end at A strike a level face, 
which gives the guide for the location of the sweep to be 
used later. The collar is adjusted to give the outer edge 
of the cover at the floor line. The surface ACB is 
swept by revolving the sweep away from the cutting 
edge as indicated at H. 

The sweep and collar are removed and the surface 
slicked for a parting surface as usual. Parting sand 
is then put upon the surface and a cope placed in posi- 
tion and staked at the corners to allow replacing after 





m 



*. • »• 



^ 




Fig. 73- 

removing for finishing the mold. A short pipe or box 
is placed around the spindle tO' allow lifting the cope 
as at P, Fig. yi,. The cope is rammed as usual with 
the necessary gates and risers. The cope is lifted off, 
finished and blackened. The pipe at the centre is drawn 
back and filled, then faced to the desired surface of the 
cope, care being used to properly vent it. A second 
sweep, E, Fig. 74, is placed upon the spindle which ex- 



148 



FOUNDRY PRACTICE 



actly conforms to the under side of the cover, having 
the edge A as a gauge for the depth and following the 
level surface previously swept. The collar on the spin- 
dle is adjusted so that the level face of the sweep just 
touches the level face previously swept, then the drag 
is swept out to the desired shape. The sweep and spin- 
dle are now removed and the face of the mold finished. 
The opening left by the spindle is filled with cinders 
nearlv to the surface, then facing sand is rammed in 
until the desired face is reached. The drag is finished 
and blackened, with the gates and risers properly con- 
nected tO' the mold. The cope may be replaced by aid of 
the stakes, which completes the mold as shown in Fig. 

75- 



pas 







h3C 




F\g. 74- 

Methods of casting fly wheels are various. Fly 
wheels are made from part patterns which are moved 
about a centre spindle. The arms are made in core, 
while the rim may be in green sand, core sand or loam. 
The method of procedure in making a mold for a fly 
wheel will be given in a general way, for the details 
can not be understood until the actual experience has 
been met with. 

The coke bed is made under the rim to extend inside 



FOUNDRY PRACTICE 



149 



part way. The socket for the spindle is set in the centre 
and below the hub cores. This socket is so leveled that 
the spindle stands exactly plumb. 

The bottom core for the hub is located about the spin- 
dle. A sweep, so shaped as to form a bed for the arm 
cores of the wheel, is then placed on the spindle. This 
sweep has its lower edge shaped like the strike stick pre- 
viously nientioned. 

The bed is rammed and struck off with the sweep over 
the entire portion within the rim of the wheel. This gives 
a bed such that when the arm cores are laid upon it the 
centre line of the arm is level. 






^ 



I-.I . • • 




•■'-■1 



I 






Fig. 7S. 

The arm cores are so placed upon the bed that their 
outer ends just touch the inner face of the pattern for t1ie 
rim. This is gauged by fastening a vertical piece onto 
the sweep previously used at the same radius as the inner 
portion of the pattern. The collar on the spindle is 
fastened so as to support the sweep above the cores. The 
cores are placed so the vertical piece on the sweep will 
just clear the end, thus giving the desired radius. 

The pattern is placed upon the spindle and the rim is 



I50 FOUNDRY PRACTICE 

rammed, a section at a time. Each time the pattern is 
moved it is kept at an exact level, thus when the last sec- 
tion is made the pattern strikes exactly where it started. 
With wheels having a straight rim without flanges, both 
faces may be rammed in green sand. Where there is a 
flange at both edges, various methods are vised. When 
the rim is light and the face less than 14 in., the lower 
flange may be made by cores laid while ramming the 
mold, and the outer face rammed at the same time. When 
large it is preferable to make the outer face in core or 
loam. The pattern then has a core print below the face 
and one above it and the green sand is rammed only on 
the inside of the rim. The cores for the face bear on the 
green sand above and below the casting and extend 
to the inner face of the flange. These cores are held in 
place by ramming the sand solid back of the cores, bring- 
ing the floor level with the top of the core. The cores 
may also be held by binding plates and supports to hold 
the outward pressure on the rim when the mold is poured. 
When the outer face is made of green sand, the top is 
covered with cores, then weighted down to hold the pres- 
sure. 

The gates are placed on the hub with a runner and 
pouring basin leading tO' the outside of the rim where it is 
accessible to the ladle. Risers are placed on the rim and 
the casting fed through the gates and the risers, when the 
rim is heavy enough to require feeding. 

Loam is used to make large molds of the same type 
as dry sand. Loam can be easily shaped by use of a 
sweep, and when dried will resist great pressures and will 
give a casting with smooth surface the same as dry sand. 
Loam is chiefly used where the whole or a part is made 
with a sweep. 



FOUNDRY PRACTICE 151 

Loam must be of a very open texture so that in gen- 
eral the mold requires but little venting. Corners, pock- 
ets, projections, and parts not havmg free relief to the 
gases are safer when vented and these vents led to the 
outside. Hard-burned brick should never be used for 
the face of the mold, as it prevents the. escape of the gas- 
es. The courses of brick are occasionally separated by a 
layer of straw tO' give better venting. 

The body portion of a loam mold is made of brick. 
This conforms approximately to the pattern or desired 
face of the mold. The bricks are laid up in courses so as 
to break joints and to bind the whole firmly together. 
They are laid in a coarse, open mixture of loam to aid the 
escape of gases. The bricks must be of a soft porous kind. 
In some cases, bricks are made from loam for forming 
portions of the brick wall. These are more porous and 
crush more easily than common bricks when the casting 
shrinks. They are made from a stifi" mixture of coarse 
loam just soft enough to work easily. The bricks are 
made in the box and laid on a plate whose face has been 
oiled, and are then dried in the oven. 

The bricks are given a first coat of coarse, open loam, 
swept to shape, and a second or finishing coat of loam 
which is finer and thinner. The thickness should never 
be less than fs in. to }i in. for plane surfaces, and not 
less than i in. in pockets, projections, etc. The thickness 
of the metal does not gauge the thickness of the loam, be- 
cause a heavy casting will scab as quickly as a thin one. 
The thicker the loam, the better the venting. 

The loam mixture is more of a mud than that of 
green or dry sand. It contains much clay combined 
with sharp sand and other materials to make it open. 
The exact mixture is entirely dependent upon the sand 



152 FOUNDRY PRACTICE 

used. In a few places the natural loam is found which 
may be used without any additions. The mixture must 
contain enough clay to hold the sand together. If the 
mixture is too weak with clay, it will crumble when 
compressed in the hand. When too strong, an exper- 
ienced mechanic can tell by the feeling, but no easy 
method can be pointed out. When the mixture is too 
weak the face of the mold will crack or crumble easily. 
When too strong or close the casting will scab, as the 
iron wall not lie quiet against it. The percent, of clay 
determines its condition. The mixture giving the best 
results can only be told when the sands to be used 
are known. Several mixtures are given below which 
give good results at different places, using the sands 
available at the particular place. These may be taken as 
general guides and varied tO' suit the sands used. The 
clay wash generally consists of 6 to 8 parts of clay to i 
of flour, wet with water to the desired consistency. 
Receipt No. i. — 4 parts loam sand, i or 2 parts sharp 

sand, I part dried horse manure. Wet with medium 

thick clay wash. 
Receipt No. 2. — 4 parts molding sand, 5 parts sharp 

sand, 1^2 parts dried horse manure, ^ part dried and 

sifted fire clay, Vj part sea coal. Wet with fair clay 

wash. 
Receipt No. 3. — 3 parts fire sand, 2 parts molding sand, i 

to 10 parts horse manure. Wet with thick clay wash. 
Receipt No. 4. — 4 parts fire sand, i part molding sand, 

I part dry riddled fire clay, i part white pine sawdust. 

Wet with thin clay wash. 
Receipt No. 5. — 2 parts loam sand, 2 parts sharp sand. 

I part old Inu'ned loam sand, i part horse manur*^. 

Wet with thin clav wash. 



CHAPTER V 

There are two types of furnace most generally used 
for remelting cast iron in the foundry. The reverbera- 
tory furnace is used in places where soft grades of fuel 
are plentiful and where special grades of iron are neces- 
sary. This type will be explained later. The cupola is 
most generally used and regarded as the most economical 
furnace. 

Fig. 76 shows an elevation and section of a New- 
ton cupola which illustrates the general type and its con- 
struction. The shell is built up of iron or steel plates riv- 
eted together. This is lined with fire brick to enable it to 
withstand the heat. The lining is of the same diameter 
from the charging door to the bottom. The bottom is 
fitted with doors which cover the entire diameter of the 
cupola so as to allow a free fall for the droppings at the 
end of each heat. On small cupolas up to^ about 30 in. 
in diameter, a single door is used. In most cases up to "J2 
in. the door is double, swinging from the centre line. In 
larger ones the door is made in more parts. 

The tapping hole or breast is located above the bot- 
tom at a height to allow the sand covering to be put upon 
the bottom doors for holding the molten metal and for 
protecting the doors from the heat. The runner or spout 
leads from the breast to conduct the metal to the receiving 
ladle. The tuyeres are openings through the lining 
for the air blast to enter. There may be one, two, or three 
rows of tuveres located at different levels. The total tu - 



154 



FOUNDRY PRACTICE 




Fig. 76. 



FOUNDRY PRACTICE 155 

yere area varies from one-tenth the cross-sectional area 
of the cupola, inside the lining, for small cupolas, to one- 
seventh, for those of large diameter. A wind-belt, or 
wind jacket surrounds the shell over the tuyeres. The 
blast is conducted to this wind belt and enters the cupola 
through the tuyeres. Peep holes are provided in the 
covering of the wind jacket opposite each tuyere. 
Through these the melter may watch the process of melt- 
ing. In the figure, a manometer is shown fastened to the 
wind jacket. This indicates the pressure of the blast. 
The amount of blast pressure varies with the size of 
cupola. The air must be forced to the centre of the fire 
to effect combustion there at the same rate as nearer the 
lining. In small cupolas the pressure varies from 4 to 8 
oz., while in larger sizes it .may be up to 14 oz. per sq. 
in. 

The charging door is placed at the charging floor. 
Its height above the tapping hole or hearth of the cupola 
should be such as to ensure complete combustion of the 
fuel, and absorption of the largest percentage of the heat 
by the charges, before passing the charging door. 

The hearth is where the molten metal accumulates. 
It is the space between the bottom and the level of the 
bottom of the tuyeres. The average height of the 
hearth is about 10 in. 

A slag notch is provided on all cupolas for drawing 
oflf the slag from the surface of the iron when running 
long heats. The slag notch is fitted similarly to the breast 
of the cupola but at a level slightly below the bottom of 
the tuyeres. It should be so arranged that the tuyere is 
not close on either side, as the cold air chills the slag 
forming bridging or obstructing the tuyere. In order 
to draw off the slag, the iron is allowed nearlv to- fill the 



156 FOUNDRY PRACTICE 

hearth up to the slag notch. The notch is then opened 
aUowing the slag to flow off the surface of the iron. 
When the iron appears, the slag notch is closed and the 
tapping hole opened to draw off the iron. 

An alarm tuyere or plugshould be provided on every 
cupola. When the metal rises to the bottom of the tu- 
yeres, it overflows first at the alarm, thus giving warning 
so the metal is not allowed to flow into the wind bell 
and eventually fill it with the iron. A common form of 
alarm is to have a groove through the lowest tuyere 
which allows the rising metal to flow off there first. Di- 
rectly below the groove a plug is fitted having its centre 
of soft metal which is easily melted. The hot iron or 
slag melts the plug, then flows to- the outside on the 
ground where it is seen. A form which gives good re- 
sults where the blast pressure does not exceed 8 oz. is to 
have a casting with open centre and tapered flanges for 
holding its cover fitted to the wind jacket below the 
alarm tuyere. The cover has a small hole about i in. in 
diameter through its centre. About 3 thicknesses of 
common paper are placed over the cover, then slid into 
place, thus making it nearly air-tight, and burning 
through almost instantly when the cupola overflows. 
This form is quick to replace, and acts more quicklv 
than most forms of alarm. 

The lining of a cupola is burned out more rapidly in 
some parts than in others. To allow renewing parts of 
the lining without disturbing the entire brick work, angle 
irons are riveted to the shell at different levels to hold 
the lining between those levels. The brick may then be 
removed between any two angle irons without disturbinr 
the remainder of the lining. 

In putting a new lining into a cupola the less clay that 
can be used between the bricks and have the joints 



FOUNDRY PRACTICE i57 

sealed, the longer the lining will last. When the clay is 
thick in the joints, it burns quickly and crumbles, leaving 
the edges of the bricks exposed to the fire thus burning 
them awav. The clay should be mixed with water, and 
very thin, so that by dipping the bricks into the mixture 
enough will adhere to form a tight joint. The bricks 
should be pressed together to scjueeze out the superfluous 
clay and to ensure a tight joint. 

The shell expands as the temperature rises, while the 
brick changes but slightly. To avoid crushing the lining 
when the shell contracts and to maintain a tight lining as 
the shell expands, a space is left between the shell and 
the brick w^ien the lining is made. This space is filled 
with fine cinders, a mixture of fire clay and cinders, or 
dry fire clay. This loose material protects the shell from 
metal breaking through the lining, and allows the shell 
to give without injuring the lining. 

The cupola must be prepared for each succeeding 
heat. At the end of each heat, when all the iron has been 
melted, the bottom is dropped to allow the slag and ref- 
use to fall out. There is always enough molten slag and 
iron left with the fuel to form a solid mass if allowed to 
cool in the cupola. Some of the refuse always clings to 
the lining so that it does not drop clean. In some cases, 
the formation on the lining projects out for some distance 
or to nearly cover the bottom. Before another heat can 
be taken off, this refuse must be removed. This can be 
done w4th a small pick or pinch bar having one end 
sharpened. The thick parts are broken off with a ham- 
m^er, then the remainder with the bar. Care must be tak~ 
en to avoid loosening or injuring the brick. Where the 
brick is glazed over, it should be left, for that glazing is 
as good protection to the brick as the clay daubing. 

After the cupola has been picked out and the lining 



158 FOUNDRY PRACTICE 

left, clean, a coating of clay is put over the lining. This 
process is called daubing the cupola and the clay mix- 
ture used is called the daubing. The best clay for this 
purpose is fire clay. Other mixtures are red or blue clay 
mixed with sharp sand in a proportion that will not crack 
open when dry, or i part of sand to 4 of clay. Too^ much 
sharp sand destroys the body of the clay so that it crum- 
bles. The fire clay is more expensive but the lining will 
last much longer than when the mixture is used. 

The daubing is spread over the face of the burned 
lining to a thickness of from Vo to i in. Where a brick 
is burned away deeper than the others, it should be filled 
in with pieces of brick mixed with the clay. This keeps 
the body of the clay thin so it will not crack or sag as 
is the case when thick in places. When the bricks are 
burned away so that the lining becomes hollowing, this 
should not be filled with the clay to make it even with 
the upper parts. If this is filled in, the clay will sag 
down and become toO' heavy to stick to^ the lining. The 
commotion of the fuel and iron against it when melting 
soon starts the clay and makes it break away from the 
iming. This produces a large amount of slag and may 
cause trouble by clogging up the cupola and stopping- the 
melting. When daubing to a thickness of ^ to i in. will 
not keep the shell from becoming red-hot during the heat, 
it should be relined with brick. 

After the lining is prepared the bottom is made. 
This consists of a sand bed on the bottom door so pre- 
pared as to hold the iron and conduct it to the tapping 
hole. The bottom, or drop, door is put up and perma- 
nently propped in place. The sand is placed upon it 
and rammed enough to compress the surface to bear 
the weight of the iron. The bottom should slope back 
from the tapping hole so as to give a free flow of the 
metal when tapped out. It should not be sloped too 



FOUNDRY PRACTICE 15.; 

much, as that gives force to the flow which makes it 
difficult to stop, and if not sloped enough, the iron may 
freeze at the tapping hole when the metal enters it. 

The sand should be very open and yet be loamy 
enough to hold together and not allow the metal to ooze 
through it. The sand may be taken from the gangway, 
or from the dirt pile. When too loamy it may bake hard 
and form a crust which will not drop, especially in small 
cupolas. Very open sand may be used, then after the 
bottom is shaped it may be coated with clay wash, which 
forms a firm crust on the surface. 

Forming the tapping hole is an important factor in 
preparmg the cupola. The portion of the cupola in front 
of the spout is called the breast. The opening made 
through the breast for the iron to flow is called the tap- 
ping hole, or port. 

The brick work is arched over the breast, leaving an 
opening for forming- the tapping hole of the desired 
depth. For the remaining distance between the inner 
edge of the tapping hole and the face of the brick the 
form is cone-shaped of such a pitch that it enlarges rap- 
idly toward tlie inside. The tapping hole should not be 
more than 3 in. long. The front may be put in before 
putting in the fuel for the bed, or afterwards by using 
the fuel for a backing to form it against. When the cu- 
pola is large enough, a good plan is to^ place a board 
against the lining to cover the breast, put the draw-plug in 
the desired position for the tapping hole, and ram or pack 
the breast into the desired shape. The plug and board 
are removed, then the inside is shaped with a trowel even 
with the brick and a conical hole to within 3 in. of the 
outside to form the tapping hole. The breast may be 
made of a mixture of clay imd new molding sand or ? 
stifif clay. It is best to form the bottom of clay for 4 or 



i6o 



FOUNDRY PRACTICE 




Fig. 76. A. 



FOUNDRY PRACTICE i6i 

5 in. in front of the tapping hole, to prevent the tapping 
bar from making a hole in the bottom. 

The spout should be lined with clay when the breast 
is put in. It is partly dried with charcoal or with wood 
before the fuel is charged into the cupola. 

After the cupola is prepared for charging, the kind- 
ling for starting the fire is placed upon the bottom. 
Shavings are placed in front of the breast for lighting 
and the wood on top of them. A sufficient amount of 
wood is put upon the kindling tO' ensure its starting the 
coke to a good fire. Coke is placed upon the wood to the 
amount of the bed charge. It is then ready to light. Iron 
should not be charged until the coke begins to burn or 
until fire shows through at the top of the bed. Iron and 
coke should be charged successively until it is at the 
height of the charging door. Succeeding charges are 
put in as fast as the previous charges settle away from 
the charging door. The charge within the cupola is kept 
to the height of charging door until the entire amount to 
be charged has been put in. This is so that the descend- 
ing charge may take up as much of the heat of the escap- 
ing gases as possible, sO' that the iron may be near the 
melting point when it descends to the melting zone. The 
charge of coke on the bed must be of an amount that wih 
hold the iron at the melting zone of the cupola until it is 
all melted. Each succeeding charge should be of the 
amount necessary to melt the charge of iron placed upon 
jt. The first charge of iron may be much larger than the 
succeeding charges, but must not be so large that part of 
it passes below the melting zone before it is melted. 

The weights of the charges for a 26 in. cupola are 
given below : 
On first charge, 390 pounds of coke on bed, 1,170 pounds 



i62 . FOUNDRY PRACTICE 

of iron. On each succeeding charge, 50 pounds of 
coke, alternating with 450 pounds of iron. 

The smaUest heat that may be taken from a cupola 
consists of the bed charge and one succeeding charge. 
The largest heat is that which may be run off before the 
tuyeres become clogged so that the melting stops. For 
long heats, a flux should be charged with the iron, which 
forms a slag of the refuse in the cupola and makes the 
slag more fluid. The slag is removed through the slag 
notch, which clears the cupola, allowing it to run long- 
er without stopping up. 

In order to produce a soft iron for machinery cast- 
ings, mix I part of soft foundry pig iron with 4 parts 
of machinery scrap iron. 

In using limestone, marble, or shells, the flux is 
charged with the iron in an amount of 30 to 50 lbs. to 
one ton of iron. 

The tapping out and stopping up of a cupola must 
be accomplished while the blast is on. After the fire is 
lighted the breast or port hole and the covers over the 
tuyeres are left open to supply air to the fire until the 
blast is turned on. The fire should be started early 
enough to allow the wood to burn out and the coke to 
become well ignited before the blast is turned on. As the 
blast is started, the covers over the tuyeres are closed, 
leaving only the port hole open. This is kept open until 
the molten metal appears, when it is closed with a clay 
ball. The blast is allowed to blow through the port so as 
to burn the coke lodged in it and ensure a free pas- 
sage for the first tap. After the metal appears it will 
keep the coke and refuse out of the tapping hole. The 
fire blowing through the port heats it to prevent the chill- 
ing of the first iron that enters it. 



FOUNDRY PRACTICE 



163 



The tools used for tapping and stopping up a cupola 
are shown in Fig. yy. The bott stick is for stopping up 
the cupola by placing a clay ball upon the disk end to 
close the port. The tapping bar is used for tapping out 
or removing the clay ball which has become baked in the 
port. The tapping chisel is used when iron or encrusta- 
tions have frozen about the tapping hole so that the bar 
can not remove them. 

In stopping up the cupola, the bott stick should be 
directed downward into the port, so that the clay is 
pressed into the hole before it dries on the face by contact 




TAPPING-CHISEL 

Fig. 77. 

with the metal. When the bott stick is forced against the 
stream of metal, it washes away or forms a crust which 
will not unite with the edges of the hole, therefore it will 
not stop the flow. The clay ball must hold the pressure 
of the blast and that of the metal head acting against it. 
Where long bott sticks are necessary, a light and stifT 
one may be made of a tube whose ends are drawn so 
that a handle is welded at one end and a rod bearing the 
disk at the other. A soft wood bott stick having a metal 
end on which to place the ball gives good service and is 
liofht to- handle. 



164 



FOUNDRY PRACTICE 



The clay for stopping a cupola must be capable of 
bearing the pressure and still not bake so hard that it can 
not be broken away with the tapping bar. A mixture for 
forming the clay balls is i part sand to 3 parts of good 
clay, then i part flour to 10 parts of the mixture. This 
will bake as a core for holding the metal and after drying 
it crumbles away easily before the tapping bar. 




Fig. 78. 

Furnaces of the reverberatory type are now used 
only where it is important to have the iron of a par- 
ticular quality or chemical combination. For chilled 
work and castings for malleableizing, the reverberatory 
furnace has some advantage over the cupola. The fuel 
required for melting a given amount is about double 



FOUNDRY PRACTICE 



165 



that of a cupola. Soft and cheaper fuels may be used. 

In this furnace the fuel is burned upon a grate and 
the metal is held in a separate division where it is not in 
contact with the fuel. The process of melting is slower, 
and the molten metal may be retained in the furnace until 
its chemical condition is that desired. Test may be made 
of the accumulated metal, and when the carbon is in the 
proper condition the metal may be tapped out and cast. 

The two general forms of furnace are shown in Figs. 
78 and 79. In the furnace represented by Fig. 78, the 
bath is immediately behind the bridge, while that shown 




Fig. 79. 

in Fig. 79 has its bath at the end remote from the bridge 
The fuel is placed upon the grates through the opening 
G. The charging door is shown at D, which is a cast 
iron door lined with fire brick. The hearth at H is where 
the metal is placed when charged. O shows the opening 
or peep holes through which the process of melting may 
be seen or the working of the metal effected. The tap- 
ping hole is shown at T at the bottom of the bath. 

The bed or bottom of the furnace is made similar to 
that of a cupola, using the same mixture or one that is 



i66 FOUNDRY PRACTICE 

more open. This bed will last for eight to ten heats, if 
it has been well dried before the first charge is placed 
upon it. The walls and roof of the furnace are made of 
the most refractory kind of fire brick, using care to have 
close joints and all crevices carefully sealed to ensure 
proper working of the furnace. 

When iron is in a molten state, the presence of oxy- 
gen will affect the carbon in the iron and burn out the 
graphitic carbon, making it harder and more brittle. The 
special object of using a reverberatory furnace is to ob- 
tain an iron having its carbon in the form desired, hence 
it is very important that cold air or oxygen should not 
strike upon the metal. The openings must be closed ex- 
cept when necessary to assist the working of the furnace. 
The entire charge for the heat must be placed upon the 
hearth before melting begins, because the furnace is so 
cooled and the metal acted upon by the cold air when a 
new charge is put in that it can not be brought back and 
the charge melted before the iron in the bath is too cold 
for use. It is similarly of importance that an even fire 
should be maintained and that no holes be caused bv 
cleaning or raking the fire, thus avoiding the entrance of 
air to the furnace through the fire. The pressure of the 
blast should be that necessary to maintain a rapid fire 
with complete combustion. The usual pressure necessary 
is from 6 in. to 7 in. of water column. 

The iron should be charged onto the hearth so as to 
leave openings between the pieces. The first layer should 
extend lengthwise of the furnace and each succeeding 
one should lie across the preceding layer. The melter 
may often hasten the process of melting by separating 
the pieces or by breaking apart those that tend to weld. 
The molten metal is skimmed, as the accumulation of 



FOUNDRY PRACTICE 



167 



dirt or scum shields the surface from the direct action of 
the flames and thus the furnace loses its efficiency. When 
various brands of iron are charged into the furnace, the 
metal is mixed by the process of "boiling," or "polling 
the metal." This process usually consists of thrusting 
green wood into the metal, causing a violent ebullition 




Fig. 80. 

throughout the mass, ensuring a homogeneous product. 
After all the charge is melted and the iron is white-hot, 
the melter dips a sample from the furnace with a small 
hand ladle for testing. If found satisfactory, the mass 
is boiled or polled for about five minutes, then the damp- 
er in the flue is closed and the furnace tapped. The iron 




Fig. 81. 

should then be poured immediately, as it will change in 
the ladles. All the operations in the furnace are con- 
ducted through the openings or peep holes, and are per- 
formed as quickly as possible to avoid keeping the holes 
open longer than absolutely necessary. 



i68 



FOUNDRY PRACTICE 




Fi-. 82. 



The vessels in which the molten iron is handled arc 
called ladles. They are generally divided into four 
classes. Hand ladles shown in Fig. 80 are handled by 




Fig. 83. 



one man and hold up to 50 lbs. of iron. The bull ladles 
are those having a double shank and are carried by 



FOUNDRY PRACTICE 



169 



two or more men. Such a ladle is shown is Fig. 81 
with the bail removed, or similarly in Fig. no, having 
the straight shank on one side. These ladles hold from 
75 to 350 lbs. of iron. The crane ladles are all those 
handled by use of the crane. There are two general 
types, those having the fixed shank with bail, as in 
Fig. 81, and those having the gearing, as in Fig. 82. 
The fourth type of ladle is used only in special places 
where suited for such use. These are mounted on 
wheels and are known as truck or car ladles, as shown 
in Fig. 83. They are used for delivering the iron from 




Fig. 84. 

the cupola to a crane ladle or to the floors where it is 
to be poured. 

The ladle is made of sheet iron riveted together, and 
must be lined with clay or fire brick to withstand the 
heat. The clay used may be about i part sharp sand to 4 
parts pure clay. When the clay itself contains sand, the 
sharp sand may be reduced. The lining is put on evenly 
from ^ to 34 in. thick and dried. The cracks are filled 
with thin clay and again dried to ensure a solid surface. 
The large ladles, as for the crane, are lined with fire 
brick laid up in fire clay, as in the case of the cupola lin- 



170 



FOUNDRY PRACTICE 



ing. A daubing of clay is placed over the fire brick to 
take the cutting and wash of the iron. The daubing is 
put on the same as the lining of the smaller ladles. In 
receiving ladles for the cupola, the continual fall of the 
iron upon one point as it comes from the spout cuts away 
the lining very rapidly. Without special protection the 
lining will be cut away in a comparatively short time. A 




Fig. 85. 

good method of daubing this ladle is to have the place 
where the metal strikes built up with small pieces of fire 
brick laid into the clay very closely, and the mass well 
bound together with the clay daubing and thoroughly 
dried before the metal strikes it. 

The blast for melting the iron is produced by blow- 
ers suitable to deliver the volume of air desired and to 
maintain the pressure required for the particular fur- 
nace. There are two types of blower in general use : 
first, the positive blast or root blower, and second, the 
fan. 



FOUNDRY PRACTICE 



171 




Fig. 



172 FOUNDRY PRACTICE 

Fig. 84 illustrates one style of a root blower which 
is driven by a belt. The blast is produced by the rotation 
of the vanes as indicated by the arrows shown in tht 
sectional view in Fig. 85. These blowers are positive, be- 
cause the volume of air delivered at the discharge side 
can not escape back between the vanes to the admitting 
side, even if the pressure is increased in the discharge 
pipe. A relief valve is usually placed on the discharge 
pipe which relieves excess pressures. 

Fig. 86 shows one form of fan blower which is driven 
by belt. The blast is produced in these by the centrifugal 
force given the air at the end of the vanes and acting 
tangentially to the rotation of the fan, thus discharging 
into the delivery pipe. The air supply is taken in at the 
centre which is left open. When the pressure in the de- 
hvcry pipe becomes equal to the centrifugal force pro- 
duced by the fan, the air will not be delivered into the 
discharge pipe, hence no further increase of pressure. 

Either of these blowers may be directly connected or 
may be driven by ropes or belts. 



CHAPTER VI. 

In many castings it is desirable that parts of the sur- 
face shall be very hard, to withstand wear and tear» 
while other parts shall retain its general toughness or 
shall be of soft iron. This result is effected by chilling 
the portion of casting desired to be hard. The chilling 
is accomplished by placing an iron chill in the mold 
where chilling is desired, while the other portions of the 
mold are formed of sand as usual. The metal coming in 
contact with the iron is cooled quickly and holds the car- 
bon in the combined or white iron form, while the parts 
cooling more slowly allow the carbon to change back to 
the graphitic or gray iron form, which is soft and tough. 

This method of hardening parts of castings is used, 
for many forms of casting and under various conditions. 
The most extensive use is that of chilling the rim of car 
wheels and the face of rolls. 

The sand parts of the mold are made similar to other 
castings, either in green or dry sand as the case mav re- 
quire. The chill portions are placed into the mold as a 
third part to the flask, as in car wheels and rolls, or are 
set similarly to a core in the side of small molds, as ma- 
chine parts, anvils, etc. The chill is heated in an oven 
to a temperature of about 200° F., before placing in the 
mold. The moisture from the mold and from the sand 
adjoining the chill would be deposited on the surface if it 
were cold, thus causing it to blow and to force the molten 
iron away from it when cast. After warming, the face of 



174 FOUNDRY PRACTICE 

the chill must be coated in order to prevent the iron from 
sticking to the surface and to allow the chill to be lifted 
from the surface. A coating of blacking wet with mo- 
lasses water gives good satisfaction. Other methods of 
coating that work better in particular cases are : to shellac 
the face and allow toi harden well before using ; to var- 
nish the face with a common grade and when nearly dry 
sprinkle with plumbago ; or to use a thin coating of a 
light clean oil, as a heavy oil or a thick coat will burn 
o&, thus holding tlie iron away by the gases formed. 

The chill should be so^ placed in the mold that the 
metal shall rise on the chill but shall not lie horizontally 
or have the inflowing metal fall upon the chill. The 
gates should be so arranged and of such a size that the 
chill will be covered quickly to prevent the metal form- 
ing bubbles on the surface of the chill. It should be 
flushed up quickly, or the chill will cause cold-shots and 
streaks in the chill surface. 

The metal in contact with the chill forms a crust or 
shell quickly and contracts, holding the remainder of the 
iron while still in the molten state. If there is any un- 
evenness in the pressure on this shell, it may cans? 
cracking or bursting of the surface, as is sometimes not- 
ed in chilled faces. This may be lessened by having the 
flask so arranged that the chill is level, as in rolls or car 
wheels. 

The chill should be made of the best grade of iron 
having little contraction, so that the surface will not 
check and bre?k when the face is suddenly heated by th-^ 
molten metal. A good iron for making chill casting will 
make a good chill. Wrought iron is sometimes used for 
a chill. The thickness of the chill is much dependen' 
upon the depth that it is desired to chill the casting. It 



FOUNDRY PRACTICE i75 

must be of such a size that it may conduct away the heat 
necessary to cool the iron from the molten state, about 
2,500° F., to that of solidification, a1 out 1,000° F., and 
must hold it at that temperature so that the iron within 
will not remelt the chilled skin. Special types of chill 
for car wheels are in use which give good results. They 
are made up of parts instead of a solid ring, and some 
forms are sO' arranged that the chill contracts as the cast- 
ing contracts, thus following the surface of the casting as 
it cools. Another form has open chambers through 
which steam is circulated to warm the chill before cast- 
ing, then cold water is circulated after casting, to effect a 
deeper chill. The depth of chill is dependent upon the 
mixture of iron used and the rapidity with which the face 
of the casting is cooled. The depth of chill on rolls var- 
ies from '1 2 in. to % in. to suit different requirements. 
Some users of rolls desire a defined chilled skin while 
others wish the chilled portion to shade gradually into the 
soft interior of the casting. Car wheels are chilled to a 
depth of about }i in. 

The mixtures of iron for chill castings can be success- 
fully made only by use of chemical analysis, and not by 
judging from the fracture. Good soft iron should have 
1.8 per cent, silicon; while this will not chill without ex-' 
cess oi sulphur, which makes a very poor iron. Chill 
iron should have less than i per cent, silicon and not 
over 0.08 per cent, sulphur. The total carbon should be 
as high as possible, other metalloids being constant. The 
combined or hardening carbon should rarely exceed 0.6 
per cent., as that makes the iron too hard and too brittle. 
The mixtures must be closely watched and tested every day 
to ensure the proper proportion of impurities. Iron melt- 
ed in a cupola is tested b-^fore pouring into the chill 



176 FOUNDRY PRACTICE 

molds. The test is for depth cf chill, and the test bar is 
about 2 in. square and 6 in. long, having one side against 
a chill. It is cooled and broken, and if the chill is insuf- 
ficient it is poured into other molds or pig beds where it 
may be remelted. The air or reverberatory furnace has 
many advantages for this class of work, as the iron may 
be tested and varied by addition of special irons before 
tapping for the purpose of pouring". 



CHAPTER VII 

Malleable cast iron is a form that becomes tough and 
partly malleable when annealed by the malleableizing pro- 
cess. The iron loses its brittleness and may be bent or 
straightened without breaking. Thus it may better re- 
sist shock and occupies a place between gray iron and 
wrought iron, having a higher tensile strength than the 
former and less ductihty than the UttQT. 

The effect of the malleableizing process is to change 
the chemical composition of the iron by action on the 
metalloids. The total carbon is reduced, making the out- 
er part nearly a wTOught iron. Tl e carbon remaining is 
changed from the hardening, or combined carbon, to 
graphitic that of gray iron. The percentages of silicon, 
manganese and phosphorus are also changed. 

The iron used must be a white iion whose carbon will 
be in the combined form. Tue per cent, of silicon must 
be low, because it tends to eliminate the carbon. When 
above 0.75 per cent., the metal will have a high tensile 
strength but small eloigaticn. The ^racture has a steely 
appearance in the finished casting when the silicon is too 
high. Phosphorus is beneficial ud to 0.15 per cent., as it 
helps maintain fluidity in the metal. Sulphur is very det- 
•rimental when present in appreciable percentages. An 
iron having sulphur or phosphorus too high will be hard- 
er and have cracks at the surface of the casting. The 
presence of manganese in comparatively high percent- 
ages is beneficial to the resulting casting. It acts as a 



178 FOUNDRY PRACTICE 

neiitralizer on the silicon to prevent its effect upon the 
carbon as the carbon changes its state. Manganese assists 
the carbon change, and shortens the time necessary for 
its completion. Scaly castings, when properly packed, 
result from too low a percentage of manganese. 

The process of annealing is effected by packing the 
boxes. They are placed in ovens which are sealed and 
castings with oxidizing reagents in^o covered cast iroTi 
heated by some form of d"rect fired furnace which holds 
the temperature uniformly at about 1,850° F. for a peri- 
od from eight hours to several days, dependent upon the 
size and character of the castings. The ovens are so ar- 
ranged as to distribute the heat evaily and not to be sub- 
jected to sudden changes. The temperature is measured 
by a pyrometer which will indicate the high temperature. 
Too high or too low a temperature affects the action of 
the reagents and injures the resulting castings. The 
oven is heated slowly so as to maintain the temperature 
of the castings at nearly that of the oven at all times, and 
is cooled very slowly when the process is complete, to 
avoid a chemical change due to the sudden change of 
temperature. These ovens may be fired by coke, coal, 
oil, or gas. 

The reagents used must be high in oxygen, which at 
the temperature of the annealing wdl combine with the 
carbon of the iron forming CO gas, which passes off. 
Some of the reagents used are red hematite ore, rolling 
mill scale well oxidized or rusted, and steel turnings 
heavily rusted. The oxidizing may be effected by a weak 
solution of sal-ammoniac. These may be used several 
times by the addition of a partly fresh unburnt reagent, 
or by reoxidizing with sal-ammoniac each time. The 
casting must be completely covered with the reagent 



FOUNDRY PRACTICE 179 

when packed in the boxes. If two castings touch, those 
spots will not be properly malleableized, thus making an 
imperfect casting. 

The form and proportions of the pattern for malleable 
work require special attention. Sharp angles must be 
avoided and all corners filleted with adecpiate radii. The 
iron always shrinks away from the angle in both direc- 
tions, thus causing a crack or depression, which should 
be avoided. The chang^e from lieht to heavv section 
should be gradual. The round section has proved to be 
the weakest form, hence it should be avoided. As the 
greatest strength of malleable castings lies in the skin, 
it is preferable to have as great a surface as possible 
with no great thickness of metal, as in many cases it is 
preferable to have several thin ribs rather than one thick 
one. 

The gating of castings to be malleableized is of great 
importance and requires the most skill and experience of 
any part of the work. For this reason most patterns have 
gates attached which are put on by experienced men. 
The cause of difficulty in gating a casting 'or running in- 
tricate forms, as in gray iron, is the hardness of the iron, 
causing it to shrink more and set more quickly. The 
branch gate should not extend from the bottom of the 
feeder, as it will chill from the sand, thus solidifying 
sooner than the metal in the mold. The feeder should 
extend about one-third its length below the branch gate 
and should be as close as possible to the casting. For 
light patterns the branch gate should not exceed Yi in. 
in length, and it is preferably of circular section. 
When it is difficult to feed a portion of a mold properly, 
a chill may be placed at that point to solidify it more 
quickly than the other parts, thus preventing fracture or 
shrink-holes. 



CHAPTER VIII 

When the casting comes from the mold it has more or 
less sand adhering to its surface, or the cores are still in 
the casting. It must be cleaned and all sand removed 
before it is ready for the machine shop. The gates and 
risers, as well as all fins, should be chipped off. This is 
a portion of the cleaning and of the preparation for leav^ 




Fig. 87. 

ing the foundry. The methods of cleaning the sand from 
castings may be classed under three main heads : First, the 
use of tumbling barrels; second, hand work; third, the 
use of pneumatic appliances. The tumbling barrel, or 
rattler, is driven by power and cleans the castings by 



FOUNDRY PRACTICE 



i8r 



their rolling about in the drum as it turns over. Fig. 
87 represents a tumbling barrel driven by the friction 
wheels on which it rests. Fig. 88 shows a pair of 




be 



tumbling barrels driven by gears and having the ex- 
haust connection for drawing away the dust as it is 
freed from the castings. 

The cleaning by hand is chiefly done by use of wire 



1 82 



FOUNDRY PRACTICE 



brushes and emerv bricks, or rub-stones. When the sand 
is fused hard onto the casting, it may require chipping, 
fiUng, or scraping with iron scrapers. The use of pneu- 
matic apphances for foundry work is increasing rapidly. 




The greatest convenience for cleaning is found ni the 
sand blast appliances as represented in Fig. 89, also as 
connected to a tumbling barrel having an exhaust con- 
nection. The sand blast is attached to the tumbling bar- 



FOUNDRY PRACTICE 183 

rel at the centre opposite to the exhaust pipe. This gives 
the action of the sand blast upon the castings as they 
move about in the tumbhng barrel. 

The gates, risers, and fins on castings are removed, in 
general, by hand chipping, or by the use of a pneumatic 
hammer shown in Fig. 94. When the gates on castings 
can not be broken and chipped without danger of break- 
ing into the casting, it is sawed off or ground off on an 
emery wheel. Many shops are equipped with cold saws 
for this purpose. All shops making steel castings must 
be provided with cold saws of some type, because the 
gates and risers must be so large that it is impossible to 
chip them off without danger of spoiling the casting. The 
emery wheel is used extensively on small castings and for 
smoothing over the chipping on other castings. The fixed 
wheel of a coarse grade is generally used. The portable 
emery wheel, or grinder, is very convenient for large 
castings. 



i84 



FOUNDRY PRACTICE 














CHAPTER IX 

The use of compressed air in a modern foundry is 
considered indispensable. By use of pneumatic tools and 
machinery the cost of foundry products is greatlv re- 
duced. The appliances operated by compressed air are 
the pneumatic crane, hoist, molding machine, sand sifter, 
chipping hammer, screen shaker, sand rammer, and sand 
blast machine. 

The pneumatic crane is shown in Fig. 90. All move- 
ments of the crane are controlled by the operator on the 
carriage. 

The pneumatic hoist is shown in Fig. 91. In lifting 
copes and drawing patterns, the most perfect and regular 
motion is required to prevent ''sticks," "tears," and ''drop- 
outs." A jerk is fatal tO' the mold. This hoist may be 
moved with a speed as slow and as regular as the hour 
hand of a clock, and a change of speed may be made 
without a sudden jerk or jar. It may be operated rapid- 
ly as well. 

A pneumatic molding machine is shown in Fig. 92. 

The pneumatic sand sifter is shown in Fig. 93. This 
machine is operated by an air cylinder directly connect- 
ed to the sifter. The air is supplied to the cylinder by a 
rubber hose, making the machine portable so that it may 
be used in any location in the foundry. 

The pneumatic chipping hammer is shown in Fig. 
94. 

The pneumatic sand rammer in Fig. 95 is fitted to 



i86 



FOUNDRY PRACTICE 




Pig. 9i. 



FOUNDRY PRACTICE 



187 







S He 



Fig. 92. 



i88 



FOUNDRY PRACTICE 



hang from a support, and has both pein and butt as the 
operator may desire. 

The sand blast machine is shown in Fig. 89. 




Fig. 93- 



Fig. 96 shows a pneumatic shaker mounted on a 
tripod so that it may be placed wherever desired and may 




tig- 94- 



FOUNDRY PRACTICE 



189 



be fitted to hold a riddle, so that a riddle of any desire:! 
number may be placed in it. 

Fig. 97 represents a pneumatic hoist having- a wind- 
ing drum driven by C}'linders. 

The machines shown in the following figures repre- 
sent a few of the special foundry machines. The sand 




Fig. 95. 

sifter shown in Fig. 98 is driven by belt but may be 
fitted with a hand wheel for hand power. 

Fig. 99 represents a rotary sand sifter which is 
belt-driven. 




Fig. 96. 



IQO 



FOUNDRY PRACTICE 




I^^igr. 97. 



I'OUNDRY PRACTICE 



191 



Figs. 100 and loi are sand mixers having paddles 
which rotate to mix the sand thoroughly. 




Fig. 98. 



Fig. 102 is a centrifugal mixer. The sand entering 




Fig. 99. 



192 



FOUNDRY PRACTICE 



from the hopper falls upon a rotating disk which throws 
the sand by centrifugal force, thus mixing it. 




Fig. 100. 

These mixers are of especial advantage in mixing 
facings or sands of different kinds where a thorough 
mixing is necessary. 

Fig. 103 represents a sand crusher. The pan hold- 
ins: the sand rotates under the rolls and the sand is loos- 




Fig. 101. 



FOUNDRY PRACTICE 



193 



ened by fixed paddles between the rolls. These paddles 
may serve as a mixer also and are used in mixing the 
sand and clay for the facing of molds for steel castings. 




Fig. 102. 




Fig. 103. 



CHAPTER X 

The mai^ufacture of steel castings is greatly increas- 
ing in extent and variety of castings made. The in- 
dustry is young, so that it has not been developed to its 
fullest extent. A few brief points will here be given 
which may give the iron worker an idea of methods 
necessary in making steel castings. 

The mold is formed in sand which may be green or 
dried to suit the type of work. The same mixtures are 
used in both cases. The sand is a very open mixture 
with sufficient clay to form a binder. The following 
mixture may be taken as a guide : 

Mix 3 parts coarse sharp sand 98% SiOo, 2 parts fine 
sharp sand 95% SiOo, i part red clay. 

This mixture should be thoroughly blended and 
crushed in a sand crusher. This is used as a facing, 
while the heap sand from former molds is used as a 
backing sand. 

The mold is rammed very hard so that in the green 
fomi it is nearly as hard as a dry sand mold for iron. 
The sand is tempered to hold together but is kept as dry 
as possible. When the mold is dried it becomes very 
hard and has great strength to resist pressure. 

Steel will cut the sand much more readily than iron. 
All edges and projections must be well nailed so that 
the heads hold the surface of the sand. All large plane 
surfaces must be nailed quite closely to prevent cutting 
in the drag and drawing down the cope. 



FOUNDRY PRACTICE 195 

Owing to the hard ramming, the pattern is hard to 
remove, hence the exact form of casting is not obtained 
so easily as in iron. Particular forms, as gear teeth, 
are more difficult to obtain in steel than in iron. 

The metal must be of a higher temperature than 
iron in order to maintain fluidity. Hence it sets more 
quickly and usually is duller when poured than iron. The 
gates must be made correspondingly large to allow the 
mold to fill quickly, or the light or sharp parts will not 
run. The shrinkage is about double that of iron, and 
takes place very soon after pouring. A riser must be 
provided of adequate size tO' feed the shrinkage. The 
feeding rod can not be used as effectively as in iron, 
hence the riser must act more as a sinking head. 

Castings of such form that they crush the sand of 
the mold when shrinkage takes place are sometimes 
found to be broken or drawn weak in places when they 
come from the mold. This is due to the casting being 
unable to crush the sand to permit the shrinkage. This 
may be prevented by cutting a gutter on the parting of 
the flask about 2 in. from the casting and connecting this 
gutter by an opening through the cope. As soon as the 
casting has set the gutter is filled with water, which 
softens the sand, making it easier to crush. In some 
cases, castings of quite intricate and large size have been 
made more successfullv in green sand than in dry owing 
to the mold's resistance to crushing. 

The chief methods of melting steel for steel casting 
are by the cupola or by a converter. Steel is success- 
fully melted in the cupola the same as iron. The higher 
temperature required ofifers many difficulties which are 
a drawback to the process. It is hard to obtain good 
fluidity in the cupola. The converter gives steel of the 



196 FOUNDRY PRACTICE 

composition desired, and the tiuidity is much more per- 
fect. 

Formerly steel was melted in a crucible, similarly to 
brass, but this is an expensive method which is not 
used except in isolated cases. The bottom blow, side 
blow, and open hearth converter are the most econom- 
ical producers of steel for castings. Where the furnace 
can be kept in operation continuously, the open heartli 
furnace presents many advantages. For intermittent 
heats, the bottom or side blow converter gives the best 
results. The side blow converter proves preferable, as 
the iron used may be lower in silicon and yet obtain a 
good steel ; and besides the steel becomes superheated, 
which better permits handling and pouring. 

In the open hearth furnace, the metal is melted and 
reduced in its bath. Any kind of iron or steel scrap may 
be charged. The product is tested by a sample and is 
poured when the steel is of the nature desired. The 
process is slow, taking from eight to twelve hours to 
reduce a charge. 

In the blow converter, the reduction takes place in a 
very few minutes. The iron for the charge is melted in 
a cupola and put into the converter in the molten state. 
The progress of the conversion is told by the gases which 
pass off at the top. When the desired amount of impur- 
ities have been removed, a charge of spiegeleisen is mixed 
with that in the converter, giving a product of the de- 
sired percentage of carbon. The steel may be varied by 
varying the percentage of spiegeleisen charged. The blast 
is turned off before charging the spiegeleisen. The two 
charges in the converter are allowed to mix, then it is 
poured out ready for the molds. 

The iron used for the converter should have about 



FOUNDRY PRACTICE 



197 



2 per cent, of silicon, phosphorus below 0.06 per cent 
manganese as low as possible, and sulphur very low. 

A mixture that may be substituted for the ore spie- 
geleisen is given below: 

95 Ibs.^ of ferrous silicate, 45 lbs. of manganese, 65 lbs 
of pig iron which is low in phosphorus and hiidi in 
silicon. 



CHAPTER XI 

Brass molding is so similar to iron molding that a 
description is unnecessary. One is different from the 
other only in the particular that gating and venting must 
be given more consideration. The sand used for brass 
molding is much finer, and when rammed in the flask, 
it must be well vented, or unsound castings will result. 
The metal used in brass casting is of a nature that will 
not permit an unnecessarily high temperature, as the 
castings will not then be sound. Long runners cool the 
metal so as to prevent its filling the mold properly. Short 
runners and a liberal amount of gating are desirable. 
The sand most used for brass molding is the Albany. 
This sand is fine and gives entire satisfaction for ordi - 
nary brass work ; but for heavy work in brass, and when 
the casting is to be finished, the mold is made in a 
coarse and more open sand. Sometimes it is advisable to 
make the mold in dry sand for heavy work. In pouring 
the metal into the mold, it should be run as rapidly as 
possible until the mold is filled. On heavy castings it is 
very necessary to provide the mold with a riser or 
shrinking head, as the shrinkage in brass or bronze is 
greater than in cast iron. After the metal has been cast 
it may be cooled in water as soon as it has solidified. 

By slowly cooling the brass becomes hard, and by 
sudden cooling the brass may be softened. The immers 
ing in water gives the sudden cooling, and besides re- 
moves the sand from the casting. 



FOUNDRY PRACTICE 



199 



In preparing the mold for brass, the ordinary facings 
used in iron molds are unnecessary. Plumbago is sel- 
dom used except in heavy castings ; for light and medium 
work, flour, pulverized soapstone, charcoal, and some- 
times plaster of Paris or bone dust are used. In very 
light castings, nothing is necessary except very fine 
molding sand. 

Very good results are obtained in small work by 
using a very fine sand and spraying the mold with gas- 
oline, lighting it, and allowing it to burn off. This 




Fi^. 104. 

skin-dries the mold and prevents the metal from wash- 
ing or cutting the mold in pouring. 

The snap flask is sometimes used in brass molding, 
but for small and for light, thin castings the flask shown 
in Fig. 104 is more convenient. This flask is provided 
with openings at one end which are used for pouring- 
holes. When the mold is ready to cast it is set on end 
with the openings up. This gives more force to the metal 



200 



FOUNDRY PRACTICE 



and greater pressure in the mold. This also avoids the 
chilling- of the metal before it reaches the mold. 

Brass founding differs somewhat from iron found- 
ing, for the reason that the metal is of a different charac- 
ter and must be treated differently. Brass, or copper 
alloys, can not be melted in a cupola furnace and sound 
castings be obtained. The metal coming in contact with 
the fuel is impregnated with impurities, which causes 




Fig-. 105. 



FOUNDRY PRACTICE 



201 



unsound castings. A simple form of furnace for melting 
brass is shown in Fig. 105. The more improved fur- 
nace is shown in Fig. 106. To prevent the metal from 
coming in contact with the fuel, a crucible is used. The 
crucible containing the metal is placed in the furnace, as 
shown in Fig. 105. The crucible is handled by means of 




Fig. 106. 

tongs, as shown in Fig. 107. The furnace is connected 
with a chimney or smoke stack of sufficient height to 
furnish draft. Mechanical draft is however applied in 
some cases. The furnace shown in Fig. 106 is sup- 



202 FOUNDRY PRACTICE 

plied with both natural and mechanical draft. This ar- 
rangement is best. While the natural draft is cheaper, 
there are days when the draft is inadequate and the 
melting slow. At such times, it is desirable to use 
mechanical draft for faster melting. Foundry coke or 
anthracite coal is used in this type of furnace. 

In Fig. 105, the portion marked A is the fire cham- 
ber, B the ash pit through which the air is admitted to 
the grate C, and D the flue connecting with the chimney 
or stack. The ash pit in front and underneath the fire 
chamber is covered by a grating which may be lifted 
off when it is necessary to remove the ashes from the 
pit. The fire chamber cover E is provided with an up> 




Fig. 107. 

right handle to enable the operator to remove the cover 
when the furnace is hot. The fire chamber is con- 
structed of fire brick and is cylindrical in form. The 
bottom plate F which supports the fire chamber is square, 
having a round opening at its centre the same diameter 
as the chamber. This plate is made of cast iron and is 
supported in the brick wall at the back and sides of 
the ash pit. The grate underneath the plate is composed 
of single iron bars placed the proper distance apart and 
supported by cross bars at front and back extending into 
the sidewalls of the pit. The single bar grate is pre- 
ferred by many, on account of the convenience in clean- 
ing the fire without rebuilding. After one heat has 



FOUNDRY PRACTICE 



203 



been taken, it is desirable to clear the furnace of cinders 
and ashes which form on the grate. This is difficult to 
do with the drop grate as shown in Fig. 106. The single 
bars may be jarred sidewise with a long bar reaching 




Fig. 108. 

through the grating on the ash pit, thus saving much 
time. 

To prepare for melting in this type of furnace, remove 
the grate bars, clear the furnace of ashes and clinkers, 
adjust the bars in their place, put in a sufficient amount 



204 



FOUNDRY PRACTICE 



of wood tO' start the coal or coke to burning, and add 
enough fuel to form a bed lo in. or 12 in. in depth. 
After the fuel is well ignited, place the crucible with 




Fig. 109. 

metal on the bed of coals and add fuel around the crucible 
to near its top. As the fuel burns away at the bottom 
of the furnace, the crucible must be raised slightly and 
more fuel added around its outside. While this is being 
done, care must be taken to prevent fuel falling inside 



FOUNDRY PRACTICE 



205 



the crucible, as this is a source of damage to the metah 
More metal may be added when that in the crucible melts- 
and settles. When the metal has become fluid enough t(> 
run well, it should not be allowed tO' remain in the fur- 
nace, but should be removed with the crucible tongs and 
poured. If allowed to stand or if overheated, the metal 
will be damaged. 

There are still more modern and improved brass melt- 
ing furnaces than those mentioned. Among others are 
the Schwartz metal melting and refining furnace and the 




Charlier rolling furnace. These furnaces are heated by 
fuel oil or gas. They are very efficient and economical on 
account of rapid melting. The Schwartz furnace is 
shown in Fig. T08. This furnace is lined with fire brick 
and is supported by trunnions having a bearing on pedes- 
tals. Air and oil are supplied at an opening through the 
trunnion at one end. The flow of oil is obtained by n 
standpipe, by pumping, or by air pressure in the tank. 
The air is supplied from a blower or from a storage tank 



206 



I^OUNDRY PRACTICE 




FOUNDRY PRACTICE 207 

of compressed air, and is regulated by a valve. Fig. 109 
is a general view of the furnace and its arrangement. 

The Charlier rolling furnace is shown in Fig. no. 
This furnace consists of a metallic casing lined with fire 
brick and having an opening in the centre of rotation at 
one end, through which the fuel and air are admitted to 
the melting chamber. The arrangement of this furnace 
is similar to the one previously shown. Fig. in shows 
a general plan of a plant equipped with a Charlier fur- 
nace. 



CHAPTER XII 



CAST IRON ALLOYS. 



To' toughen cast iron: lo to 15 per cent, of wrought 
iron scrap (stirred in) ; ^4 to i per cent, of copper 
(stirred in). 

To toughen cast iron or to form semi-steel : Add fron^. 
5 to 30 per cent, of steel scrap to the charge of iron in 
the cupola. 

To harden scrap iron: Mix ^ pint vitriol, i peck com- 
mon salt, y2 lb. saltpetre, 2 lbs. alum, ^ lb. prussic 
potash, y^ lb. cyanide potash. Dissolve the mixture in 
10 gals, of soft water. Heat the iron to a cherry-red 
and dip intO' the solution. For a harder and deeper 
skin on the iron, repeat the heating and dipping two 
or more times. 

To soften or to anneal cast iron : Heat to a cherrv-red, 
then pack in a coating of bone-black and cover with 
ashes to allow cooling very slowly. 



GLOSSARY 

Air-dried — The surface drying of cores left in open 
air too long before placing in oven. Molds left open 
also dry out on surface, causing crumbling or washing 
when metal is poured. 

Air hoist — a piston and cylinder suspended from an 
overhead track or traveling crane and operated by com- 
pressed air. For hoisting ladles, flasks, or weights in 
the foundry. 

Alloy — any compound of two or more metals, as 
copper and zinc to fonn brass. 

Anchor — a contrivance used to hold parts of the 
mold down or together. See Pulley anchor. 

Arm — the portion of a puUc}^ which connects the 
hub and the rim. 

Ash pit — the space underneath a fire box, in a core 
oven or brass furnace, to receive the ashes which fall 
from the grate. 

Bars — the framework inside the cope of a molding 
flask, to retain the molding sand in position while lifting 
or handling the flask, and also to resist the pressure of 
metal when casting. 

Batten — a piece attached to a thin flat pattern for 
the purpose of strengthening and keeping it straight; 
not a part of the pattern nor to be a part of the casting. 
It should be marked "stop-ofT," and the recess formed 
by this piece in the mold should be filled up or stopped 
off after the pattern has been removed from the sand. 



210 GLOSSARY 

Bed charge — the first or lower charge of coke in a 
cupola, reaching from the bed or bottom to a point above 
the tuyeres. 

Bedding in — the process of molding a pattern by 
embedding it in the sand in the exact position in which 
it is to be cast. 

Bellows — an instrument for forcing air through a 
tube. Used in foundries for the purpose of blowing away 
loo'Se sand from the molds. 

Binders — the various articles used in loam, core 
sand, and facings for the purpose of holding the sand 
together when dry, such as glue w^ater, molasses, lin- 
seed oil, flour, etc. 

Blacking — a thin facing of carbon, consisting of pul- 
verized charcoal or plumbago, by which the fusible in- 
gredients of the sand are protected from the intense heat 
of the metal when casting. Blacking is sometimes ap- 
plied as a powder to green sand molds; but for dry sand, 
loam, or skin-dried molds and cores wet blacking or black 
wash is used. Wet blacking consists of common blacking 
mixed with water thickened with clay to the consistency 
of thin paint. Wet blacking somewhat hardens the sur- 
face of a mold when dry. 

Black lead. — See Graphite. 

Blast — the current of atmospheric air delivered 
from the blower or fan under pressure through the 
blast pipe and tuyeres into the cupola. 

Blast gauge — the blast gauge is a device to de- 
termine the amount of pressure in the wind belt or 
jacket of a cupola while in operation. This instru- 
ment is a form of manometer. 

Blast pipe — the pipe through which the air passes 
from the fan or blower to the cupola. 



GLOSSARY 211 

Blower — a box with revolving" wings or vanes in- 
side, so constructed and arranged as to force a pres- 
sure of air through the blast pipe into the cupola. 

Blow-holes — holes occurring in castings, due to air 
and gas in the metal and in the mold when casting. 
Blow-holes are the result of insufficient venting and of 
moisture. 

Bott stick — a stick of wood or bar of iron with one 
flat end on which to place a ball of clay in stopping the 
flow of iron from the cupola. 

Bottom board — the board on which the flask rests 
when in position to cast. It may be of iron or wood. 

Breast — the clay front built in the opening over the 
spout of the cupola and through which the tapping port 
is made. 

Bricking up — building up the skeleton of a loam 
mold by means of bricks cemented together with loam. 

Bull ladle — a vessel for handling- molten metal. It 
is placed in a shank and is carried by two or more men. 

Burning on, or casting on — the process of mending 
cracked or broken castings or of adding on metal, where 
the casting is unsound or incomplete, by means of flowing 
molten metal over the part to be treated until fusion takes 
place. 

Burnt sand — sand which has had contact with 
molten metal. The sand which forms the face of a 
mold invariably becomes burnt. 

Butting, or butt ramming — the process of butting 
or ramming the sand with the flat end of the rammer. 

Camber — the curving of certain types of casting in 
cooling, due to want of symmetry in their sectional 
forms, by reason of which one portion cools ofif more 



212 GLOSSARY 

rapidly than the other, causing distortion of figure in the 
longitudinal direction. 

Carrier — a casting which is attached to the arm of a 
gear molding machine and to which the tooth block is 
attached. 

Casting — a piece of metal work obtained by pour- 
ing molten metal into a mold. 

Casting on — the same as burning on. 

Changing hook — an S crane hook which is double 
at one end and which is useful in transferring from one 
crane to another. 

Chaplet. — Chaplets are iron supports to retain a 
core in its proper position where core prints can not be 
used. 

Chaplet block — a block of wood rammed in the sand 
to receive the spike of a chaplet nail. The block afford?; 
the requisite steadiness to the chaplet when in position. 

Chaplet nails — a chaplet with one end flat and the 
other a sharp point to be driven into the bottom board 
or into a block of wood rammed up in the sand which 
forms the mold. 

Charcoal — coal made by charring wood. It is used 
in drying molds. Oak charcoal pulverized is used for the 
purpose of blackening molds. 

Cheek — an intermediate part of a mold where more 
than two parts are necessary. 

Chill — a metal form placed in a mold or forming a 
portion of the mold against which the iron is poured to 
produce a chilled casting. 

Chilled casting — a casting whose surface is hard- 
ened by pouring molten iron against a chill. 

Cinder bed — a bed or layer of cinders or coke placed 
below a pit mold for the purpose of carrying off the gases 



GLOSSARY 213 

that pass downward. The cinder bed is connected to the 
surface by a vent pipe. 

Clamps — are wrought or cast iron bars whose ends 
form a right angle ; they are useful in binding together 
the top and bottom of a flask while pouHng the metal. 

Clamping — placing the clamps in their proper posi- 
tion on the flask when the mold is completed. 

Clay wash — a mixture of clay and water. 

Coke bed. — See Cinder bed. 

Cold shots — small globular particles of metal which 
are formed by the first splashing of metal in a mold and 
which harden c|uickly and do not amalgamate with the 
other metal in the mold. 

Cold-shuts — are produced by pouring the metal too 
cold or too slowly into the mold and are due to imperfect 
amalgamation of the metal in the mold. They may also 
be caused by gases in the mold, arising from the use of 
facing sand containing too great a percentage of sea coal. 

Contraction. — See Shrinkage. 

Cope — the top part of a flask or mold. 

Core — a body of sand in the mold for forming inte- 
rior openings or holes in the casting. 

Core barrel — a hollow bar or pipe on which a cylin- 
drical core is formed. The barrel giyes the core strength 
and also openings through the sides, affording yent for 
the gases generated in casting the metal around the core. 

Core board — a board whose edge is profiled to a sec- 
tional form of a desired core. 

Core box — a box in which a core is to be formed or 
molded. Its interior shape to be the same as the outside 
form of core desired. 

Core carriage — a carriage upon which the cores are 



214 GLOSSARY 

placed after being molded and on which they are con- 
veyed into the drying oven. 

Core irons — rods or bars of iron rammed up in a 
core to give it strength. 

Core lathe — a frame having V's or bearings in 
which to place a core barrel provided with a crank, on 
which barrel a core is to be formed and trued up by 
revolving the core against a sweep which forms the 
desired shape of the core. 

Core mixture — a core sand dampened and mixed 
with a binder in such proportions that when dry it will 
become hard. 

Core oven — an oven in which to bake or dry cores 
after molding them. 

Core plate — a plate on which cores are formed or 
placed while drying. 

Core print — an attachment or projection on a pat- 
tern which forms a seat or pocket in the sand in which 
the core is to be placed in the mold after the pattern 
has been removed. 

Core rope — ropes or strings used for forming vents 
in crooked cores, from wdiich rods or wires could not be 
withdrawn without damage to the core. 

Core sand — any sharp sea sand or nearly pure silica. 

Core trestles — upright standards or trestles whose 
tops are provided with V-shaped recesses or bearings in 
which to place the ends of a core bar or barrel while re- 
volving to sweep up a core. 

Core wash. — See Blacking. 

Crane — a device for lifting and moving' heavy 
weights in a foundry, such as flasks, weights, and 
ladles of molten metal. 

Crane ladle. — See LadJe. 



GLOSSARY . 215 

Crushing — compressing the sand in the mold by 
too great strain on the clamps after the pattern has 
been withdrawn, causing the mold to crumble and sand 
to fall into the mold. 

Crystalline fracture — where the face of the break 
shows a coarse formation of crystals. 

Cupola — a cylindrical furnace for melting iron. A 
cupola is lined with fire brick and provided with ports 
or tuyeres near its base through which a pressure of 
air is forced. 

Cutting over — the process of shovelling over the 
sand to obtain an even mixture and temper. 

Daubing — lining or plastering up the interior of a 
cupola or ladle with clay or molding sand. The operation 
is performed w4th the hands. 

Dov^ell — a pin of wood or metal used to hold the 
parts of a divided pattern in their respective positions 
while they are being rammed in the sand. 

Draft — the allowance or slight taper made on a pat- 
tern to aid in its removal from the sand after being 
rammed up. The portion of the pattern at the parting 
line of the mold must be larger than that extending into 
the cope or drag. 

Drag — the lower part of a mold when in position 
to be cast. 

Draw. — The casting draws when the shrinkage 
causes depressions of the surface or openings in the in- 
terior. See Drawing. 

Drawback — a section of a mold rammed up sepa- 
rate from the drag and cope and parted by a plate or 
piece of cloth, and which may be drawn back for the 
convenience of the molder in removing the pattern or 
in patching the mold. 



2i6 GLOSSARY 

Drawback plate — the iron plate on which a draw- 
back is rammed up. 

Drawing — removing the pattern from the sand 
after the mold has been formed, also increasing the 
depth of a mold without altering the dimensions of the 
pattern by drawing the pattern a part of the length up- 
ward and ramming the sand around its upper portion. 

Draw plate — a plate attached to a pattern for the 
purpose of receiving the rapping iron and lifting screw. 

Draw spike — a tool pointed at one end to be driven 
into the pattern for the purpose of lifting it from the sand. 

Drop-out — the whole or part of the sand falling out 
of the cope of a mold while turning over or closing a 
flask. 

Drying — the process of evaporating moisture from 
a mold by means of hot air injected, or of a charcoal 
fire basket, or by baking in an oven. 

Dry sand — mixtures of sand which after being 
dried in an oven or otherwise becomes hard and better 
resists the strain from molten metal. 

Dull iron — iron which has not been heated to a 
proper temperature, or which has been allowed to re- 
main in the ladle too long before pouring. Dull iron 
causes seams, cold-shuts, and unsound castings. 

Facing — any material used to mix with the sand for 
the purpose of preventing the fusion of the sand and the 
metal. Pulverized sea coal is commonly used. 

Facing sand — the mixture of sand which forms the 
face of the mold. 

Fan — an apparatus provided with revolving wings 
enclosed within a case for the purpose of forcing air 
into the blast pipe of a cupola. 

Feeder head — a body of molten metal contained in 



GLOSSARY 217 

a riser or opening above a mold for the purpose of sup- 
plying metal to the mold when shrinkage takes place. 

Feeding — forcing- the metal into the mold from the 
feeding head during the time it is liquid by means of an 
iron rod kept in motion vertically in the feeding" head. 
It is sometimes termed pumping a mold. 

Feeding rod — a wrought iron bar used for the pur- 
pose of feeding a mold. 

Fin — a thin projection on the casting at the parting 
line of the mold, caused by an imperfect joint. 

Fire clay — a kind of clay which will sustain intense 
heat and which is used in furnaces, cupolas, and ladle 
linings. 

Flask — a box or frame in which a mold is formed. 
A flask must consist of two or more parts and may be 
made of either wood or metal. 

Flow-off gate — a vertical passage through which 
the metal flows after the mold has been filled. Its top 
is lower than the level of the pouring gate. 

Flux — any material used in a melting furnace or cu- 
pola to cause the slag to become more liquid and more 
easily drawn off before tapping out the iron. Limestone 
is commonly used. 

Follow-board — a board which conforms to the form 
of the pattern and defines the parting surface of the 
drag. 

Foundation plate — a plate of cast iron placed in the 
bottom of a mold to receive the spindle to maintain a 
sweep. 

Founding — the casting of metal in molds. 

Fusing — the iron and sand are said to fuse wdien a 
hard coating of sand adheres to the metal after casting, 
due to the heat of the molten metal. 



2i8 GLOSSARY 

Gaggers — are made of iron in the shape of the letter 
L and are used for the purpose of anchoring the sand to 
be hfted in the cope of a mold. 

Gangway — the passages between the molding 
floors and leading from the cupola. The gangway is 
usually laid with iron plates over which trucks or ladle 
carriages are run. 

Gate — the terminus of the runner where the metal 
enters the mold. The opening through the cope left by 
the gate stick is commonly called the gate or sprue. 

Gate cutter — a piece of thin sheet metal bent to the 
shape of the letter U ; it is used to cut the runners which 
conduct the metal to the mold. 

Gate stick — a wooden pin or stick used by the 
molder to form the opening leading from the pouring 
basin to the runner. It is placed in position before the 
sand is rammed in the cope. 

Grab hook — hooks connected by short chains or 
rods for the purpose of attaching loads to the crane 
hook. 

Graphite — carbon in one of its conditions, distin- 
guished by its usually crystallizing in foliated, six- 
sided prisms, though often massive, by its softness, by 
its metallic luster, and by leaving a dark lead-colored 
trace on paper. It is often called plumbago or black 
lead. 

Green sand — common molding sand suitably tem- 
pered to form molds for metal without subsequent 
drying. 

Gutters — shallow channels cut at the parting of a 
mold for the purpose of receiving the vents which are 
led off at the parting and of conducting them to a relief 
vent. 



GLOSSARY 219 

Hand ladle. — See Ladle. 

Hard ramming — ramming the sand in a mold until 
hard. Some molds should be rammed hard to resist the 
pressure of the metal. 

Hatching up — cutting or roughening the surface of 
a mold for the purpose of better holding new sand 
which may be added in patching. 

Hay rope — hay twisted or spun to the form of a 
rope, used to wind around a core barrel or hollow bar 
in striking up round cores or loam. The hay holds the 
sand or loam to the bar and also affords escape for the 
gases. 

Hot metal — metal which is in its most liquid state. 
Light and thin castings should be poured with hot metal. 

Ladle — an iron vessel lined with fire clay and used 
in handling molten metal from the cupola to the mold. 
Hand ladles are carried by one man and bull ladles by 
two or more. Crane ladles are handled by the crane. 

Leveling — making a bed of sand level by the use of 
parallel strips, a straight edge and a level. 

Leveling strips — parallel strips used in leveling 
sand beds. 

Lifter — a tool used for removing loose sand from 
the bottom of deep molds. 

Lifting screw — an iron rod with a screw or thread 
cut at one end and an eye or loop at the other. The screw 
may be used in the wood pattern and the thread in a 
tapped plate attached to the pattern. 

Lift off — to remove a portion of a mold after ram- 
ming up. 

Loam. — Loam sand is a mixture of sand, clay and 
venting material such as horse manure, that gives a firm, 
hard, but open-grained body when dry. The mixture 



220 GLOSSARY 

must be regulated by the class of castings for which the 
loam is to be used. 

Loam board — a board the edge of which is profiled 
to a sectional form of a mold which it is to strike up. It 
is swept around a vertical bar to which it is bolted. 

Loam mold — a mold constructed of loam. 

Loam plate — a plate of iron cast in an open mold 
and studded with spikes upon which the brickwork of 
a loam mold is built. 

Loose piece — a portion or projection made detach- 
able from the body of a pattern for convenience in 
molding. 

Melting zone — a space above the tuyeres in a cupo- 
la where the greatest heat is obtained. 

Mold — the matrix or reverse form of a pattern 
made in sand. 

Molding — the process of forming a mold in which 
metal is to be cast. 

Molding machine — any machine by which the oper- 
ation of molding is performed or the drawing of a pat- 
tern is made safe and expeditious. 

Molding sand — sand used for the purpose of form- 
ing a mold, and possessing the quality of resisting the 
pressure of molten metal as well as the heat. It also 
must be porous or open when compressed in order to 
allow the free escape of the gases generated by the 
heat of the metal. 

Nowel — the bottom portion of a mold when in po- 
sition to cast. Commonly called drag. 

Old sand — sand which has been used for the pur- 
pose of molding until it becomes old, black and burnt 
from contact with the molten metal. 

Open sand molding — molds formed in the floor of 



GLOSSARY 221 

the foundry and having no cope or covering. Only cast- 
ings having one flat side or surface can be formed this 
way. The mold must in all cases be perfectly leveled. 

Parting sand — sand used for the purpose of pre- 
venting two parts of a mold from uniting. It causes 
the sand to part when the flask is opened after ram- 
ming. Sharp sand or burned core sand is commonly 
used. 

Patching — the process of repairing a mold after the 
pattern has been removed from the sand. 

Pattern — a model from which to form a mold. Its 
impression in the sand forming a mold in which to pour 
molten metal to form a casting. 

Peeling. — A casting is said to peel when the mold- 
ing sand and iron do not fuse. After the casting has 
cooled the surface of the metal is left smooth and free 
from sand. 

Pit molding — forming a mold in a pit dug in a foun- 
dry floor. Light pit molding is usually of green sand. 

Plate anchor — the anchor used in a pulley anchor 
having plates to cover the surfaces between the arms.' 

Plate molding — dividing the pattern at its centre 
and placing each half on one side of a parting board 
which is provided with pin holes corresponding with 
the pins of interchangeable flasks. The drag and cope 
may be rammed on opposite sides of the board, and 
after the board has been removed the flask may be 
closed. 

Plumbago — a mineral consisting chiefly of carbon. 
It is used for blacking and for facing. It is properly 
called graphite, but often called black lead. 

Pouring — the emptying of the molten metal from 
the ladle into the pouring basin or gate of a mold. 



222 GLOSSARY 

Pouring basin — a reservoir or basin formed on the 
cope of a mold to receive the molten metal and from 
which it flows into the gate. 

Pulley anchor — the part of the mold of a pulley be- 
tween the arms and the face of the cope. 

Pulley foot — a cone or pyramid placed in the an- 
chor of a pulley mold for the purpose of ensuring re- 
moving and replacing to the same position. The pul- 
ley foot may be separate and placed in the anchor 
while ramming, or it may be a part of the anchor, as in 
a plate anchor. 

Rammer — a tool used for the purpose of ramming 
the sand in the flask and around the pattern. The 
rammer is usually made of iron. One end is called the 
pein and the other the butt. The pein end is rectangu- 
lar in section and the butt end is round and flat. 

Rapping — the process of loosening the pattern from 
the sand while yet in the mold. A bar is inserted in the 
pattern and is rapped sidewise in every direction tuitil 
the sand compresses and is free from the pattern, after 
which the pattern may be easily withdrawn. 

Rapping bar — a bar of iron either pointed or 
threaded at one end to be inserted into a pattern for 
the purpose of rapping. 

Rapping hole — a hole bored in a pattern or in a rap- 
ping plate let into the pattern to receive the rapping bar. 

Rapping plate — an iron plate screwed to or let into 
a pattern having a hole to receive the rapping bar. 

Reverse mold — a dummy mold on which a portion 
of an actual mold is to be rammed. 

Riddle — a sieve for sifting sand for the purpose of 
molding. 

Riser — an opening from the mold to the top of the 



GLOSSARY 223 

flask through which gases may escape and the surplus 
metal rise above the upper surface of the casting. 

Runner — a channel cut in the sand to conduct the 
metal from the pouring basin to the gate. 

Sand sifter — a mechanical device for the purpose of 
sifting sand. 

Scabbed castings. — Scabbed castings are those on 
the surface of which rough and uneven projections ap- 
pear. Scabs occur from various causes, such as im- 
perfect venting, improper ramming, unsuitable ma- 
terial, too rich facing sand, excess of moisture, etc. 

Scrap — that which is of no use in its present form. 
The old castings which are only good for the metal in 
them, or castings which can not be used, are called scrap. 

Sea coal. — Sea coal is ordinary bituminous coal. 
When pulverized and mixed with molding sand, it is 
called sea coal facing. 

Shrinkage — contraction of metal while cooling 
after casting. 

Shrink-holes — openings in the surface or in the in- 
terior of a casting caused by the shrinkage of the metal 
in cooling. 

Sinking head — the prolongation upon a casting ver- 
tically tO' supply metal to replace shrinkage. The ex- 
cess length is cut off, leaving the desired casting. 

Skeleton core box — a frame or skeleton in which to 
form a core without a full core box. Skeleton core boxes 
are commonly used in forming one-half of a round 
core by means of a strike stick. 

Skim gate — an arrangement of gates, runners, and 
risers which will effect the separation of the impurities 
before the metal enters the mold. 

Skimmer — a bar of iron usually bent to the shape 



224 GLOSSARY 

of the letter L at one end for the purpose of prevent- 
ing- the slag" and dirt from following the metal as it 
flows from the ladle to the pouring- basin of a mold. 

Skimming — the holding back of the slag and dirt 
on the surface of molten metal wdiile being poured from 
the ladle into the mold. 

Skin-drying — the process of drying the face of a 
mold. 

Slag — the refuse from the cupola, caused by im- 
purities of the metal and fuel as well as by the fused com- 
pounds of the silica and alumina in the lining- and 
(laubhig. 

Slag hole — a port hole in a cupola slightly below 
the level of the tuyeres for the purpose of tapping out 
the slag before tapping the iron. 

Sleeking. — See Slicking. 

Slick — a tool used for smoothing the surface of a 
mold. An ordinary trowel may be used for a slick. 

Slicking — smoothing and finishing the surface of a 
mold with a trowel or slicking tool. Sometimes spelled 
sleeking. 

Sling — a device made of iron or of rope for the pur- 
pose of handling flasks or weights. The sling is used to 
connect the crane tO' a w^eight or to the trunnion of a 
flask. 

Snap flask — a small flask used in ^:."nch molding 
having a hinge at one corner and a lat^Ji at the diagonal 
corner. 

Soldiers — strips of wood used by the molder to 
strengthen or to anchor bodies of sand. 

Socket — the base for supporting the spindle in a 
sweep mold. See Foundation plate. 

Spongy. — A casting is spongy when honeycombed 



GLOSSARY • 225 

by blow-holes. The centre of a casting may be spongy 
from shrinkage of the metal in solidifying. 

Spout — a box or gutter lined with clay to con- 
duct the molten metal from the tapping hole to the 
ladle. 

Spray can — a can fitted with a blow-pipe or bellows 
so that the liquid in the can may be forced out in a 
spray or mist. 

Sprue — the casting formed in the gate of a mokL 
See Gate. 

Staking — the setting of the cope on a pit in the 
mold by means of stakes. 

Stopping off — the process of filling up a portion of 
tlie mold which is not desired to^ be cast. 

Stopping-off piece — a piece used as a guide or tem- 
plate in stopping off. A stop-off piece is a duplicate of 
the desired casting at the point stopped off on the pat- 
tern. 

Stopping over — filling up with sand the space over 
a core placed in a print pocket. 

Straining — the distortion of a mold by the pressure 
of the metal, usually caused by insufficient ramming of 
the sand. 

Strike stick — a straight edge or form beveled at its 
edge for the purpose of cutting the sand or loam in 
building up a mold or core. 

Stripping plate — the plate which holds the sand in 
place while the pattern is being drawn. 

Strong sand. — Molding sand is called strong when 
it contains clay and when upon drying it becomes hard 
and will not crumble. 

Swab — a substitute for a brush for dampening sand 
in a mold or around a pattern before it has been removed 
from the sand. Swabs are usually made of hemp. 



226 GLOSSARY 

Swabbing — the dampening with a swab of the joint 
edges or interior sections of a mold for the purpose of 
strengthening the sand and causing it to be more plasti-; 
and coherent. 

Sweep — a board having the profile of a desired 
mold. A sweep must be attached to a spindle and re- 
volved around the spindle to give the mold the proper 
form. 

Tap hole — the hole through the breast of a cupola 
through which the metal flows. 

Tapping — opening the port of a foundry cupola for 
the purpose of allowing the metal to flow into the ladle. 

Tapping bar — a long bar of iron pointed at one end 
and having a loop at the other to serve as a hand hold. 
It is used for the purpose of opening the tap hole in a 
cupola to allow the metal to flow out. 

Tempering sand — the process of dampening and 
mixing the sand preparatory to ramming a mold. 

Test bar — a bar of iron cast for the purpose of test- 
ing the strength of the metal. 

Trammel — another name for a beam compass. 

Traveling crane — an apparatus arranged on over- 
head tracks and so constructed as to move a load in 
any direction. 

Trowel — a tool similar to a mason's trowel, used in 
slicking, patching, and finishing a mold. Trowels are of 
various shapes and sizes. 

Tucking — compressing the sand with the fingers 
under flask bars or around gaggers or soldiers where 
the rammer can not be used. 

Turning over — the operation of inverting the drag 
of a mold with the pattern in the sand. The top and 



GLOSSARY 227 

bottom are covered with boards, clamped up, and turned 
over. 

Turn-over board — the board upon which a pattern 
is placed wdiile ramming up the drag of a mold. 

Tuyeres — the openings which admit the air blast 
to the interior of a cupola or blast furnace. 

Vents — any means provided for the escape of gases 
or of steam generated by contact of molten metal with 
cores or molding sand. 

Vent gutter — a groove or an opening cut in the 
sand to conduct the gases away from the vents. 

Venting — the process of making vent holes or open- 
ings in the mold by means of a vent wire, or otherwise, 
to allow the gases to escape while casting. 

Vent strings — strings used for the purpose of vent- 
ing crooked cores when wires or rods could not be em- 
ployed without damaging- the core. Sometimes wax 
strings are used and melted out in drying the core. 

Vent wire — a small rod or wire used in forming a 
vent. 

Weak sand — sand having a very small percentage 
of clay, thus having but little strength at the usual 
temper and hardness. 

Wedges — small V-shaped pieces for the purpose of 
blocking under a clamp or over a chaplet. Wedges may 
be of wood or of iron. 

Wet blacking. — See Black wash. 

Wind jacket — the chamber surrounding a cupola 
into wdiich the air is forced from the blast pipes and 
from which it enters the tuyeres leading to the cu- 
pola. 



TABLES 



Melting Points of Different Brands of Iron 



Combined 

Carbon 
Percentage 


Graphite 
Percentage 


Character 

of Fracture 

Grav 
White 


Melting 

Point 

Deg. F. 

2210 

2000 


Remarks 


1.60 
4.67 


3.16 

• 03 


Samples cast 
from same ladle 


1-57 
4.20 


2.90 
.20 


Gray 

White 


2250 
1990 


Samples cast 
from same ladle 


W 
1.20 

3-90 


2.90 
.16 


Grav 
White 


2250 
2000 


Samples cast 
from same ladle 



Melting Points of Solids 



Cast Iron 


3477 deg. 


Lead 


6co deg. 


Wrought Iron 


3981 deg. 


Zinc 


741 deg. 


Gold 


2587 deg. 


Cadmium 


602 deg.. 


Silver 


1250 deg. 


Saltpetre 


600 deg. 


Steel 


2501 deg. 


Tin 


420 deg. 


Brass 


1897 deg. 


Sulphur 


225 deg. 


Copper 


2550 deg. 


Potassium 


135 deg. 


Glass 


2377 deg. 


Antimony 


951 deg. 


Platinum 


3077 deg. 


Bismuth 


476 deg. 



Metal Alloys (values represent proportional parts) 



Copper Tin Zinc Lead Ant'm'y Bism'th 



Brass valves 


9 


I 


.50 






- 


" bearings 


10 


1.^0 


.50 








Bell metal 


15 


5 










Yellow Brass 


36 


2.50 


17 


2.50 






Gun metal 


9 


1 










Fine solder 




I 




I 






Plumber's solder 




I 




2 






Cast Iron " 




2 




I 






Babbitt metal 


I 


10 






I 




Metal to expand in cooling 








9 


2 


I 


Type metal 








9 i 


I 




Hard Bronze for lathe bearings 


80 


20 




i 







230 



TABLES 



Chilled-Roll Iron 




Gun Carriage Iron 



1 m-i6 



1. 122 
1.664 

I.8S9 



2.780 

9.250 

11 .820 



2.174 

2.714 



2.812 
4.264 

4-355 



.100 
.110 
.100 



Car Wheel Iron 



1/8 
1^/8 
I 15-16 



1. 174 
1.690 

2 . 008 



2.200 

8.100 

13.500 



1.082 


2.033 


2.244 


3.610 


3.167 


4.263 



.053 

.070 
.072 



Heavy Machinery Iron 



11 
12 



1/8 
1^/8 
I 15-16 



1.187 
1.705 
2.001 



2.800 


1 .106 


7.100 


2,282 


1 .900 


3.143 



2.530 

3.111 

3.786 



.092 
.072 
.079 



Stove Plate Iron 



13 
14 
15 



iH 
1 ic,-i6 



1.182 

1-745 
2.047 



2.500 
6.050 
9.900 



[.097 

2.391 

3.288 



2.288 
2.530 
3.011 



-117 

.078 
.081 



Bessemer Iro.^i 



16 


iH 


^•J75 


2.150 


1.084 


1-983 


.100 


H 


1^8 


1.698 


5.500 


2.263 


2.430 


.100 


18 


1 15-16 


1.991 


8.900 


3.112 


2.860 


.085 


19 


I in. square 


•994 


1-757 


.988 


1.778 


.150 



Chemical Analysis of Irons Described Above 



Class of Iron 



Chill iron 
Gun metal 
Car wheel 
General machinery 
Stove plate 
Bessemer iron 























TD 




c 




:3 

"5. 


c 

03 

be 

B 




0. 


.S 

a rt 


II 


If} 


r. 






d'^ 


0^ 


.84 


.071 


.285 


.547 


.61 


2-45 


-73 


.059 


.408 


•453 


.76 


2.47 


.78 


-132 


.306 


.364 


1.07 


2.36 


1.30 


-053 


.224 


.433 


.58 


3-31 


2.47 


.094 


.265 


.508 


-19 


4.00 


1.52 


.059 


.326 


.083 


-49 


3.73 



o t; 

H to 
U 



3.06 
3.23 
3-43 
3-89 
4.19 
4.22 



TABLES 



231 



Size and Capacity of Foundry Ladles 






n 



w ^ 



Capacity 

in 

pounds 

50 

100 

150 

200 

250 

300 

350 

400 

500 

600 

700 

Soo 

1000 

1200 

1500 

2000 

2500 

>00 

3500 

4000 

4500 

5000 

6000 

'Sooo 

10,000 

12,000 

14,000 

16,000 

18,000 

20,000 

24,000 



Inside dimensions 


Al'vvsfo 


rdaub'g- 


AI'vvs at 

top over 

cap'c'ty 

ins. 


Diameter 


DeiJtli 
in. 


at bot- 
tom in. 


at sides 
in. 


Top in. 


Bottom in. 


S.25 


6.25 


6 


.50 


-375 


.^0 


10 


9 


9.50 


1 


.50 


1 


50 


II 


10 


10.50 


I 




50 


I 


50 


12 


II 


11.50 


I 




50 


I 


50 


13 


12 


12.50 


I 




50 


I 


CO 


14 


12.50 


13 


1 




50 


I 


50 


14. So 


13 


13.50 


I 




50 


I 


50 


15.50 


14 


14.50 


1.25 




75 


I 


75 


16.50 


15 


15.50 


1.25 




75 


I 


75 


17.50 


16 


17 


1.25 




75 


I 


75 


18 


16.50 


17.50 


1.25 




75 


I 


75 


18.50 


17 


18 


1.25 




75 


I 


7C 


20.50 


18.50 


19.50 


1.50 




2 


21.50 


19.50 


21 


1.50 




2 


23 


21 


22 


1.50 




2 


25.50 


23-50 


24.50 


1.50 




2.50 


27 


25 


26 " 


1.50 




2.50 


28.50 


26 


27.50 


1.50 


I 


2.50 


30 


27.50 


29 


1..50 




2.50 


31-50 


28 . 50 


30 


1.50 




3 


33.50 


30.50 


32 


2 


1.50 


3 


34-50 


31 


33 


2 




50 


J 


36.50 


33 


35 


2 




50 


3 


40.50 


36.50 


38.50 


2.50 




75 


3 


43-50 


39 


41 


2.50 




75 


3.50 


45.50 


41 


43.50 


2.50 




75 


3.50 


48 


43 


45-50 


2.50 




75 


3-50 


50 


45 


47-50 


2.50 




75 


3-50 


52 


46.50 


49 


2.50 




75 


3.50 


53-50 


48 


50.50 


2.50 




75 


3.50 


57 


51 


54 


2.50 


2 




3- 


50 



Shrinkage of Castings (approximate values only) 



Metal 



Cast Iron 
Brass 
Tin 
Zinc 

Steel 



Inches per lineal foot 

.125 

.1875 
-833K 
■ 3125 
-25 



232 



TABLES 



Weights of Castings from Patterns where No 
Cores are Used 



A pattern, weigh- 
ing I lb., made of 


will weigh when cast in 


Cast Iron 
lbs. 


Zinc 
lbs. 


Copper 
lbs. 


Y'Tw Brass 
lbs. 


Gun Metal 

lbs. 


Mahogany, Nassau 


10.7 


10.4 


12.8 


12.2 


12. s 


Honduras 


12.9 


12.7 


iS.3 


14.6 


15.0 


" Spanish 


8.5 


8.2 


10. 1 


9-7 


9-9 


Pine. Red 


12.5 


12.1 


14.9 


14.2 


14.6 


White 


16.7 


16.1 


19.8 


19.0 


19-S 


" Yellow 


14. 1 


13.6 


16.7 


16.0 


16.5 


Oak 


9.0 


8.6 


10.4 


10. 1 


10.9 



Weights of One Cubic Foot of Metals with their 
Tensile Strength 



Metal 



Cast Iron 
Ordinary Brass 
Wrought Iron 
Hard Structural Steel 
Aluminum 



Weight of I cu. 


T 


ensile strength per 


ft. in pounds 




sq. in. in pounds 


450 




16,500 


525 




36,000 


480 




50,000 


490 




78,000 


166.5 




26,800 



Weight in Pounds of One Cubic Inch of Different Metals 



Brass (average) 


.3023 


Zinc, cast 


.26 


Bronze 


.306 


Antimony 


.242 


Copper, cast 


• 3135 


Bismuth 


.3S5 


Gold, pure 


■ 6965 


Manganese 


.289 


Iron, cast 


.2622 


Silver 


.378 


Iron, wrought 


.282 


Platinum 


.735 


Lead, cast 


.415 


Cadmium 


.312 


Steel 


.281 


Potassium 


.031 


Tin, cast 


.263 







Mixtures for Phosphor-Bronze Bearing Metal 



Number of 


Copper 


Lead 


Tin 


Phosphorus 


mixture 


per cent. 


per cent. 


per cent. 


per cent. 


I 


79.0 


10.0 


10 


i.o 


2 


79-7 


9-5 


10 


.8 




79-7 


10.0 


10 


.3 



TABLES 



233 



Size and Capacity of Crucibles 



Number 


Outside 


Greatest 


Capacity in 


of 


height 


outside di- 


molten 


crucible 


inches 


ameter in. 


metal lbs 


1 


3-50 


3 


3 


2 


4 


3.25 


6 


3 


4.625 


3.75 


9 


4 


5.125 


4-25 


12 


c; 


6 


4.625 


15 


6 


6.50 


5.125 


"18 


8 


7.25 


5-875 


24 


10 


8.25 


6.25 


30 


12 


8.625 


6.50 


36 


14 


9.125 


7.25 


42 


16 


9.625 


7.75 


48 


18 


10 


8.125 


54 


20 


10.625 


8.625 


60 


2S 


11.125 


9 


75 


30 


11.75 


9-375 


90 


35 


12.25 


9-75 


105 


40 


12.625 


9 -'^75 


120 


45 


13 


10.50 


135 


50 


13-75 


10.75 


150 


60 


14.125 


11.25 


180 


70 


14-75 


11.75 


210 


80 


15.50 


12.50 


240 


100 


16.125 


13 


300 



INDEX 



Bedding in, 69. 

Blow-holes and shrink-holes, 42. 

Brass, molding of, 19S; founding 
of, 200; melting furnace for, 
201 ; same for fuel oil or gas, 
206. 

Burning on or casting on, 43. 

Castings, feeding of, 27; chilled, 
173; malleable, 177; cleaning 
of, 180; steel, 194. 

Cast iron alloys, 206-207. 

Chaplets, described, 31 ; se cting 
and wedging of, 34. 

Clamping or weighting of cope 
and cores, 38. 

Columns, molding of, 102. 

Compressed air, 184. 

Coping out, 65. 

Cores, setting and venting of, 
29, 77; cover, 92; described, 
110; ramming of, 112; wires 
and rods for, 112; baking or 
drying of, 115; pasting of, 128; 
nearly submerged, 132. 

Core anchors, 130. 

Core barrel, 123. 

Core box, 124; skeleton core box, 
126. 

Core-making machines, 136. 

Core mixtures, J 20; core blacking 
mixtures, 122. 

Core ovens, 116. 

Core plates, 130. 

Cupola, preparing of. 157; tap- 
ping out and stopping up oi, 
162. 



"Ks, 6. 

.eels, methods of casting, 
J- 18. 



Follow-board, 45. 

Foundry blowers, 170. 

Foundry ladles, 167. 

Furnace cupola, 153; reverbera- 

tory, 169; brass melting, 201; 

same for fuel oil or gas, 206. 

Gaggers, 20. 

Gears, molding of, 106. 

Hay rope machines, 122, 

Loam mixtures, 151. 
Loam molding, 150. 

Molding, bench, 44; plain, 53; 
with divided pattern, 61; open 
sand, 72; of columns, 102; of 
gears, 106; pit, 143; loam, 150; 
brass, 198. 

Molding machines, 47. 

Molds, venting of, 11; parting of, 
14; gating of, 15; patching of, 
24; stopping off of, 26; crush- 
ing of, 40; match for a, 45; dry 
sand, 137; finishing dry sand, 
139; blacking dry sand, 139; 
drying dry sand, 140. 

Nailing or rodding, 23. 

Pneumatic chipping hammer, 

184. 

Pneumatic crane, 184. 

Pneumatic hoist. 189. 
Pneumatic molding machine, 

184. 

Pneumatic sand rammer, 184. 

Pneumatic sand sifter, 184. 



236 



INDEX 



Pneumatic shaker, 188. 
Pouring basins, 20. 
Pulley anchors, 98. 
Pulley rings, 96. 

Risers, 16. 

Sand, molding, 1; tempering of, 
1; cutting over of, 1; riddling 
of, 3; facing, 4; ramming of, 
9; parting, 15. 

Sand blast machine, 188. 

Sand crusher, 192. 



Sand mixers, 191; centrifugal, 

191. 
Sand sifter, rotary, 189. 
Shrinkage, 41. 
Skim gates, 17. 
Soldiers, 22. 
Steel, casting of, 194. 
Sweeps and spindles, 145. 

Three -part work, 79. 
Tools, molders', 8. 
Tumbling barrels, 180. 

Vent gutters, 134. 



SEP 6 1904 



